Generally, any top rated game from that period which doesn't rely on "realistic" graphics but instead offers very good gameplay and is kind of timeless and ages well.
For example, you shouldn't play the original System Shock 1 anymore, although it was top tier in 1994, because its graphics are very poor for today's standards, it's UI has always been poor, and it's a game that fully relies on immersion, but you can't immerse yourself anymore if both graphics and UI are really poor. Instead, play the System Shock remake from Nightdive Studios which came out recently. It's not the same, but it's very similar, and much better nowadays. Also why you shouldn't play the old STALKERs anymore, although they were amazing and it kind of saddens me to write this, but they really don't offer much immersion today, which is why they didn't age well. I'm writing this because I didn't finish part 3 back in the day and intended to finish it like 2 years ago, but I couldn't stand the dated graphics anymore. For a game which relies fully on immersion, that ruins it.
Here's my list (not in a particular order), I'm focusing on PC games because I never really play that much console or handheld stuff:
Command and Conquer up until Red Alert (remastered version available). These are classic RTS games in a sci-fi war setting. Some say Total Annihilation was the best RTS during the 90s but I never played it.
Starcraft 1 (remastered version available). This game is also still being played competitively in multiplayer, with an active tournament scene, especially in South Korea. Also great in single player. Famous for its balance, at least on modern tournament maps.
Age of Empires 2 (remastered version available). It's like a mix between a classic RTS and Civilization. Great game, lots of content by itself already, also tons of added content.
Jagged Alliance 2 (great community mods available). You can skip part 1, part 2 was absolutely amazing. A great strategy and tactics based game. It's quite difficult, but great.
Doom 1+2 (remastered version available, very recently updated again on Steam (this month!)). Plenty of 3rd party engines like gzdoom also available which make them look and feel much more modern. Tons of community-made content as well. Special mention: John Romero, one of the original level designers, also made more content over the years (e.g. "Sigil"), which is great as well.
Quake 1+2 (remastered version and 3rd party engines available). These were among the first games fully utilizing 3D-accelerated graphics back in the day, so they pushed boundaries and they brought the pseudo-3D games like Doom 1+2 into a full 3D environment.
Baldur's Gate 1+2 + its expansions (remastered version available). Also highly recommend version 3 of course but that's not an old game. Plenty of mods available for them as well. These are all exceptional RPG games with great story and depth that no RPG fan should skip. They also age well because it's just good 2D art.
Planescape: Torment (only if you a) liked Baldur's Gate and b) don't mind reading (it's a lot of text) and enjoying a complex story with complex character interactions. Remastered version available)
Half-Life 1+2 (instead of HL1, play "Black Mesa" which is a great modern remake (not the same, but very similar and much better nowadays). For HL2, there are also some remastered versions or mods available, and Valve updated the game engine from time to time so when you download it today, it's not the dated version from 2004 anymore). HL1 (1998) was one of the first FPS with a really great story line, voice acting, and stuff like that, which is why it pushed boundaries back when it was released. HL2 was just excellent overall and one of the first or the first game which introduced physics-based object manipulations, so it again pushed boundaries further)
Sin Gold was a great FPS from 1998 that got brutally overshadowed by Half-Life 1, but it's still a great story-based shooter, more action-focused. Based on an updated Quake 1 engine.
Portal 1+2. Best to play them after you've played the Half-Lifes. Portal 2 (2012) is THE highest rated game on Steam (https://steamdb.info/stats/gameratings/). Truly great puzzle FPS set in Half-Life's setting, which is why it's useful to know about HL before jumping in (but not a requirement). Portal 1 also isn't far off in rating. Portal 1 was basically a "side game" for the Valve game compilation named The Orange Box, Portal 2 was then a true AAA quality followup because Portal 1 was a huge success.
Deus Ex 1 (maybe. Graphics are really poor (they were already dated when it launched). But it was one of the first RPG-FPS with stellar level design and the freedom to approach every situation in different ways, so VERY good on the gameplay side). Deus Ex 2 is supposedly bad, so skip that. The newer ones like Human Revolution and Mankind Divided are decent but they're not classics anymore they're still """fairly recent""", around 2010 or so.
System Shock 2. It also looks very dated by now but there are some HQ mods available (improving models and textures) which make it more bearable. I'm hesitant to mention it because it relies a lot on immersion and it looks very dated. So according to my own recommendations, I probably shouldn't list it, but it's also great in level design and gameplay, and its art style never was ultra-realistic to begin with, so I'll list this one as an exception. It's very much worth playing, truly a great sci-fi/horror RPG-FPS and a worthy successor to part 1. Nightdive Studios might be working on an SS2 Remake or Remaster, if so then I'd say wait for that!
There are even more great adventure games from LucasArts or Sierra back in the day, but you'll have to figure them out for yourself. I will only recommend Monkey Island because they were probably the most successful and well-known ones. For some of them, remasters are available, or you can play them using ScummVM. There were also other great adventures not from LucasArts or Sierra, like Simon the Sorcerer. The 80s, 90s and early 2000s spawned a lot of great point+click adventure games.
Diablo 2 (remaster available). D1 started the whole "genre" of hack&slay action RPGs but it's rather poor in comparison and aged terribly, D2 is much better in all areas, so skip D1 and instead try D2.
Z (very unique and fun RTS game from the 90s. If you haven't played it, you should! It offers very good and unique gameplay that no one else really tried to copy as far as I know, which is a shame. It truly emphasizes unit production time, speed and good timing). It's also entertaining. And difficult.
Thief Gold + Thief 2 (remasters available I think, but even if not, despite the graphics being very dated, a lot of it is in shadows anyway and IMHO the general art style kind of ages well, though that may be subjective, and it's also immersion-based, so YMMV, but I think it's fine still). Also "The Dark Mod" as a community "continuation" of the series). If you like stealth FPS, you must play them. Thief 3 is also decent. Any Thiefs after that are terrible. There are amazing community-made mods/missions as well.
Alien: Isolation. This one is from 2012 I believe, so not quite old, but an honorable mention because it's also an amazing stealth-based game. Its art style (like the first movies) also makes it age better. In fact I'd say this is one of the best horror-based stealth games ever made.
Heroes of Might & Magic 3 (I think in this case, the remaster is bad. Stick to community mods/patches). This one is still the best of the series, so you don't need to play any other part. Ages very well because it has very beautiful 2D-based graphics. Great art and design overall.
There was one old RPG which supposedly aged very well but I didn't play it yet. Maybe Albion or Lands of Lore, not sure what it was.
Tomb Raider 1-3 (remaster)
WH40k Dawn of War 1 is great if you like the universe and RTS games in general. Also the best in the series.
XIII (Thirteen) - but not the new remake, play the original. It's a rather unique stealth-based, comic-look based FPS. Ages quite well because of its unique look (utilizes the kind of shading like Borderlands)
Elder Scrolls 3-5 are very good as well but you need several mods or engine enhancements, otherwise graphics aren't that good anymore, and these are games which rely on good graphics as well for atmosphere/immersion. So they don't age well by default, but thankfully they have a VERY active modding community which keeps these games alive. You can even make them look very modern, but it takes time and effort to do so.
Nethack (somewhat of a nerd game, terrible graphics by design (text-based art style), but amazing and very deep/complex gameplay, very rewarding to get into, if you don't mind its presentation. In terms of gameplay depth it brutally outclasses most games on the market). There are also some other clones like Slash'Em which I didn't play. Dwarf Fortress is probably similar in depth and presentation (but very different in gameplay and general type of game) but I also didn't play it yet. If you know enough about Nethack it's also not that hard, but getting to that point is very difficult and if you don't know anything then it's very difficult. (I've done 8 ascensions, i.e. 8 finished playthroughs).
Honorable mention because it's technically not old but looks old: Return of the Obra Dinn. Don't skip this one, it's one of the best games I've ever played, I'm not kidding. It's truly amazing, and it's made by 1 guy. It's a perfect example of why graphics fidelity in games doesn't matter that much and you can create excellent, modern-feeling, stylish games regardless.
Super Metroid because it's amazing, and Castlevania Symphony of the Night for the same reason. I may be biased because those are two of my favorites ever but I swear they legit hold up.
Starwars Knights of the old Republic 1 and 2 they are on steam and kotar 1 can be played on a phone.
AC blackflag.
Dragon age origins.
If you want a more specific recommendation based on a old gaming system let me know.
There are entire genres that I think in many ways have passed younger gamers by.
Point and click adventures were the biggest thing in the world at one point. The classics are the Lucas Arts entries, like Indiana Jones and The Fate of Atlantis, The Dig (both based on unused Spielberg pitches), the Monkey Island games, Full Throttle, Day of The Tentacle and Loom. You've also got Myst and Riven (Riven being the far superior of the two), and my personal favourite, The Longest Journey, which has an absolutely stellar story and really compelling protagonist with a lot of depth to her. Also, positive queer representation in a nineties game, holy shit.
The next lost nineties genre is the space sim. The kings of the genre were Wing Commander and X-Wing/Tie Fighter. Then you've got Privateer and later Freelancer. For the Wing Commander games read a summary of 1 and 2, then jump in with 3, the first to feature FMV with Mark Hamill as the player character (genuinely an excellent performance too, he took the role really seriously and saw it as every bit as important a scifi property as Star Wars). John Rhys Davies (Gimli) and Malcolm McDowell also make appearances.
And of course, the classic nineties FPS, a genre that feels very, very different from modern FPS games, though there have been some good attempts to recreate it. You know Doom, and Wolfenstein 3D (the latter does not hold up; the former absolutely does), but also check out Heretic, Hexen, Rise of The Triad, and most importantly, IMO, the Marathon games. These were the precedessors of the Halo series, and they combined really solid action with a genuinely amazing story. It's the kind of big, high concept that you rarely get in movies, TV shows and games, with a world that the writers clearly put a tonne of thought into, and some characters who will stick with you long after the game is over.
Finally, some stuff that doesn't really fit any of the above. Crusader: No Remorse and Crusader: No Regret are isometric action shooters with some fun storytelling and LOTS of explosions. If you get them on GOG be sure to download and read all the supplementary material, it really fleshes out the world and the characters. System Shock probably doesn't even need mentioning with the recent remake, but the originals truly hold up, especially with the UI and controls polish Nightdive added. Syndicate and Syndicate Wars are very hard to explain, but they're really fun (That said, I'll give an even stronger recommendation to their modern spiritual successor, Satellite Reign, which deepened the gameplay significantly while still retaining all of the spirit).
There's plenty more, obviously, but that's what immediately comes to mind as worth checking out.
The Bard's Tale - Hilarious, and I am a sucker for anything that involves summoning a squad to fight for me.
Psychonauts - Absolutely delightful. Just cute, funny, weird and imaginative. The platforming itself is good, though it gets really hard towards the end.
Eternal Darkness - By far my favorite horror game. None of the terrible controls, bad cameras, or bullet sponge enemies beating you with a wet noodle to give the impression of danger. Just a lovecraftian horror story full of great atmosphere and character, with the twist that as your character's sanity meter goes down, shit gets weird, and sometimes breaks the fourth wall.
Skies of Arcadia - I cannot stress enough just how much I love this game. Sky pirates flying between floating islands in endless sky during an age of adventure and exploration.
The Zelda Series - The original is still worth playing, but you'll want to look up the map that it came with. A link to the past is beloved, but Link's Awakening is the real nostalgic one for me (I have the switch remake and haven't had a chance to try it yet). I still think Ocarina of Time holds up, but I understand that many disagree. Majora's Mask is great in many ways, but it is a game that works best when you have a lot of time to explore and discover things on your own, and as a grown ass adult with a Job and responsibilities, I had trouble going back to it and not just looking stuff up in a guide, which diminishes things... I also don't have time to list my thoughts on the entire series.
KOTOR 1 & 2 - Pretty much what I wish every new iteration of Star Wars would aspire to be. The second one is a bit more uneven, as it had a vision that was truly inspired, but was forced out on an extremely rushed time frame, so a lot of things got cut, and even the restoration mods can't add everything back in. (Also, Dragon Age Origins, as long as we're talking classic Bioware)
Star Wars Republic Commando - A great FPS with a squad that actually knows how to do their jobs, and which does a good job of showing the clone wars from the perspective of a soldier. (Honorable mention to Jedi Outcast and Jedi Academy which are still the best Jedi based action games but which had some technical issues the last time I tried to play them)
Castlevania Circle of the Moon - Everyone talks about Symphony of the Night, and I won't argue with them, but my all time favorite in the series has to be Circle of the Moon. Refined Castelvania gameplay with a unique magic system that is simple but satisfying.
Punchout (with or without Mike Tyson) - The original is a classic and it holds up surprisingly well.
Halo 1, 2, 3 ODST, and Reach - They each hold up in their own unique way. The first one is immersive and is extremely well polished mechanically. The second has a stronger story and adds the bonus of being able to swap weapons with teammates (give them the scoped weapons, keep them alive, live or die as a unit), the third has awesome mechanics but weaker storytelling, ODST is Halo 3 Band of Brothers Edition, and Halo Reach actually tells the best story while taking the gameplay back to its roots.
Cursed Halo - It's Halo 1, but completely insane. It manages to actually be fun while also being completely ridiculous.
Rollercoaster Tycoon. Super chill game, you just manage amusement parks and build rollercoasters. Openrct2 is an updated engine for it, which supports modern high resolution screens, but requires a copy of the game for the art assets.
Tron 2.0 - A FPS game set inside computers from the early 2000s. There were a lot of great weapons in the game but I always went back with the Disc throwing weapon.
Homeworld 1/2/Cataclysm- An 3D space RTS series 1999/2000s. During the campaign all units made carry through to the next mission.
Lots of great suggestions here, but if you've never played the original Super Mario Bros, Super Mario Bros 3, and Super Mario World, you should. There is a reason they're considered classics and everybody should experience Mario's roots. My 8 year old plays them every so often and he keeps progressing.
SMB 2 is a good game as well, but it's quite different from the others. It is the origin of a few series staples, though.
Morrowind is hands down the best elder scrolls. If you want a TRUE sandbox where you can do whatever the hell you want, that's your game. Some issues include graphics, no quest markers (you have to read the quests and follow directions), the leveling system is not intuitive at all, and combat is heavily stats based.
Upsides are you can craft any spell or enchanted item using any spell effects you know. Ring of permanent invisibility. Spell of lock every door within 50 feet. Summon 3 different daedra at once. Conjure a whole set of bound armor. Explode yourself in fire. Literally anything.
The elder scrolls renewal project is working on recreating morrowind with skyrims engine and I really hope it comes out soon.
It's not super old, but the original BioShock is one of those games that you can point to and say "this is art". It's an amazing exploration of Ann Rand, capitalism, addiction, art, deregulation, unions, and greed, all with the most beautiful art deco levels. The mechanics of the powers you get are tied into the themes and your choices of how to acquire them are in themselves a statement of the self vs others. It's well thought out from the ground up, from aesthetic choices to narrative ones, and one of the few games that absolutely nails it.
I enjoy the gameplay of the second one even better, though I feel the attempt to explore collectivism doesn't fit as well by using the same motifs as the first one, the dlc Minerva's Den has the most tragic exploration of identity and the singularity out there.
The third is fun to play but I think they were trying to explore too much of everything at once, between America, racism, classism, quantum states and everything else, and unlike the first two, the mechanics of the plasmids didn't really lend anything to the story. The dlc is fun, but rewrote a poignant lesson from the base game and watered it down.
Most good platformers from the 80s and 90s still hold up: Super Mario Bros., Super Mario Bros. 3, Super Mario World, Sonic the Hedgehog 2, Sonic 3, Sonic & Knuckles, the Donkey Kong Country Games...
The Atari 2600 was before my time, but I bought one at a flea market when I was a kid and was actually impressed by how fun a lot of those games were: Laser Blast, Outlaw, Warlords, and Missile Command, to name a few. The problem is that the hardware is pretty important to the experience. The responsivemess (or lack thereof) of those old controllers is part of the design, so I'm not sure they'd emulate well.
Once you get into the early 3D era, it's hard for me to say what's actually good and what's nostalgia. I love Goldeneye, and it revolutionized the FPS, but it's probably a pretty bad experience if you didn't grow up on it. I'm pretty sure Mario 64 is still a legitimately good; it seems like it was still well received on the Switch, and it's core mechanics have remained basically the same through Sunshine, the Galaxy games, and Odyssey. I think Legend of Zelda: OoT is still legitimately good, but it's hard to tell. I certainly still enjoy playing it, and it think it's worthwhile just to see the origins of Z-Targeting, but I'm sure it does feel dated. Either way, you should play the N64 version of Majora's Mask for sure. It's still the strangest, darkest Zelda game, and the 3DS version was shit.
Finally, most turn-based RPGs are going to hold up, but I want to make special mention of Pokémon Gold, Silver, and (especially) Crystal. It's become trendy in the last few years to say these games are actually bad because of a bad level curve, a bad post game, and some other assorted complaints. The level curve criticism is fair, but the post game is great, and most of the other issues are just people who are upset it didn't follow some of the conventions set by later games. I could say a lot about it, especially if I got into it's connectivity with RBY, Stadium, and Stadium 2, but I'll just say it's still one of the highlights of the franchise, and a contender for greatest sequel of all time. Every fan of the Pokémon should play Crystal at least once.
This will probably get buried but I got a few of em for ya.
Syndicate Wars: Game was mind blowing for the time it was released.
Black and White 1/2: I know, more Peter Molyneaux. Everything else has been mentioned.
Jade Cocoon 1: Not 2. One was extremely unique and you won't find another game like it. It's the coolest monster merging game I've seen and has an endless dungeon.
Dungeon Crawl Stone Soup: It's old but not old. Went open source and has been developed over some time by the community. It's much more newbie friendly these days.
Warlords Battlecry 3: Holy cow the races, persistent hero progression in an RTS. It's age shows though.
That's all I can pull of the top of my head right now that I haven't seen mentioned, though I didn't skim every single comment.
Edit: Just remembered Tyrian existed. Oldschool Schmup that had a good SP campaign and multiplayer.
one of my favorite games of all time: Prince of Persia 1989 (1990 on PC). it's a "cinematic platformer" where the animations take priority over responsiveness.
once you get the hang of it, it's incredible what Jordan Mechner could fit into a ~1MB game controlled with just 5 keys. the realistic platforming and sword fights were unlike anything I'd seen. still impresses me to this day.
it's kind of notorious for being a hard game you have to finish in an hour, but I think it's a must play. I always felt like it was one of those zero-fat games. no filler, no repetition without a curveball thrown in every now and then.
flashback and blackthorne were two more in the genre that i really really enjoyed before 3d games came along and ruined the momentum of the genre. other people will suggest another world (aka out of this world) but that one, while iconic and unique, will feel more antiquated by today's standards and works more like a puzzle than the rest.
If you're into the '90s extreme aesthetic, I'd definitely recommend Comix Zone to get you neck-deep in it.
You play Sketch Turner, a comic artist who- along with his pet rat, Roadkill- gets sucked into his own comic by the comic's villain, Mortus, who wants to trap Sketch forever so he can exist in the real world or something.
It's a side-scroller beat 'em up where you move across the panels and pages of a comic book, punching and kicking mutants while the Sega sound chip blasts (occasionally grating but still awesome) grungy rock at you. If you're into '90s shit, there's nothing not to love
I still think Metal Gear Solid 1,2, and 3 hold up very well in terms of story and gameplay. The controls take a bit of getting used to, if you're used to how modern games play, but once you get the hang of it they are really an experience.
Spend an hour or two tweaking everything to the max, without disintegrating the entire map with one banana, then a couple of hours of practice, and you've got the ultimate party game
RPG: Star Ocean 2, Breath of Fire 3, Grandia 1 and 2, Chrono Trigger and Chrono Cross, Zelda link to the past, Secret of Mana, Final Fantasy 9, Skies of Arcadia, Legend of Heroes series (start with trails in the sky), Persona series (start with 4), FF Tactics series, Tactics Ogre series, Phantom Brave series
Fighting: Tekken 3, Soul Calibur, Rival Schools, Power Stone 1 and 2, SNK vs. Capcom
Racing: Ridge Racer series, Tokyo Xtreme racer series, Colin McRae rally series, Burnout Paradise, FlatOut series
Shooters: Mars Matrix, Einhander, Cotton series, Ikaruga, Bangai-o, Rez
Fps: Time splitters 2, Red Faction series, Quake series, anything in Orange Box, Rise of the Triad
Adventure: Beyond good and evil, Devil May Cry series, Gurumin, Sleeping Dogs, Syberia series
Platformer: Klonoa Series
I ran out of brain but maybe I'll add more when I wake up.
I am not sure if tfc (team fortress classic) still has servers running in any capacity, but it was one of the forefathers of role based, team shooters. It's influence and by proxy TF2's is still huge in competitive gaming.
Alright lots of recommendations in here, some that are making me question how old I am now since some of these don't strike me as old enough to require a recommendation but I'll just suggest one as a bit of a dark horse.
Tyrian 2000, the classic PC Shmup of a time long gone. Oh and I guess Jazz Jackrabbit cause that soundtrack is funky.
Half life, if you really can't get into it check out black mesa but please try the original first it is amazing and was truly ground breaking. Then play the portal games because they expand on eachother.
Not that old, but Prince of Persia: Warrior Within (2004).
I have not played that many games, but I have yet to find such an amazing action adventure combat mechanics.
There is a trailer on Youtube that does the system justice - everything can be done in-game, at your will, and it's not even that hard. Context matters, and it's so rewarding chaining different combos to plow through them like butter.
Those basic enemies are meant to be fucked up in every possible way, the environments often provide ample varieties of opportunities.
Then there are stronger enemies and bosses, which don't let you mop them around, so you have to fight them face to face.
The game itself is decent, there are some bad platforming parts, but thanks to time rewind they can be beaten.
The biggest issue is very low native resolution, and the game kept crashing on my Steam Deck. I will try it again, because I want to relive that combat again.
Many of the old Sierra and Dynamix adventure games are great. Kings Quest IV through VII are probably the ones that hold up best. The adventures of Willy Beamish, Heart of China, Police Quest and Space Quest.
Commander Keen - Goodbye galaxy. Completely different but it's right up there with Zelda for SNES.
Museum Madness - insanely creative and supremely educational game with an abssssurd amount of content for the time that must have taken ages to build. It's the basics of major educational subjects so most would (hopefully) be review but it's well done and the path to learn each piece and sub-ppieces requires constantly rejiggering your mind. Also a great way to teach modern kids how damn persistent you had to be to figure something out.
Oregon Trail
Where in the ______ is Carmen San Diego
Scorched Earth
SNES- super Street fighter 2 turbo, NBA jam TE, Ken Gruffy baseball, Zelda link to the past, supermarioworld, Earthworm Jim
N64- Mario kart 64, Mario golf, Goldeneye, 1080 snowboarding, blitz NFL, Gretsky 3d hockey, DK Country
GTA2 - top down view and sound effects were fantastic.
Worms Armageddon. Like comparing Doom to Pong, this for me was the ultimate level of what started with Pong/cannon fodder/scorched earth. It took all that and made it hilarious and graphic and incredibly memorable. Easy to learn, difficult to master, top 5 party game ever.
Warcraft 2 is hard to go back to because of some of the QOL improvements war3 introduced but the sound board from war 2 may never be outdone.
Tribes online was one of the first mostly open world team based team fps I played. Some of the vehicle mechanics were clunky but many games never even bothered to try to implement such features before or since.
Diablo II - years of my life. Obligatory fuck Duriel
Unreal Tournament 2004 - weapon selection, play style and map variety options with bots that weren't great but much better than what had preceded them. Graphics were incredible at the time and for me still look good on some levels.
Max Payne - the time slowing feature, consistent and well done noir theme and feel and an enjoyable narrative make it one that even though I only played through twice I remember 20 years later.
You might enjoy crpgaddict, a blog that is playing through every computer roleplaying game in chronological order, providing scores for each one on various metrics. The reason I bring him up is that he doesn't rate on a curve, or give things marks for being "good for its time" - if pool of radiance scores higher than skyrim, it's not because it was influential or good for its time, but because he thinks it's outright better regardless of age (just an example - I'm not saying he would actually rate those two games that way, and he has not rated skyrim). There are early 80s games that he remembers fondly and had a huge impact on the industry that he rates as like 23/100 or whatever, because the scale leaves room for the Witcher 3.
It takes a long time to get through all those games, so he's currently up to the early 90s, having updated his blog regularly for over a decade. But his list of highest rated games might be a good place to start.
Oh, and while we're talking about old-ish RPGs that would score well on his scale, I might as well mention Morrowind and the Baldur's Gate series (before 3, obviously), which he won't reach for a long time but has been known to hold up as solid examples of the genre. Personally I still think Baldur's Gate 2 is great. I'm also a big fan of the quest for glory series, which crpgaddict has rated, but might not make his list of top scoring RPGs, because they're a hybrid adventure/RPG, so not all of their strengths appear on a scale designed for pure RPGs.
Maybe I overlooked it, but I didn't see any mention of Jade Empire yet. This is one of the master pieces from Biowares golden age. The setting and story are wonderful and they aced the characters and how you interact with them.
And Diablo II is also still a master piece of action RPG. The flow in playing it is masterfully done.
It is a puzzle game like Myst but the puzzles make more sense, less like rubbing 2 coconuts on everything until they fit, and the world has more life to it.
There's a lot of great stuff here, I'm going to add morrowind but seriously, mod it, I love the game but it's definitely of its time, controls aren't terrible (a bit alien but workable) but the combat didn't age well, all dice rolls so while it looks like you should connect it's all chance. Game itself gives the player a lot of freedom of choice, tons of ways to play it too.
Red Faction (PS1, PC) - Just one of my favorite series. One of the early FPS's with destructible environments. Continued with a series, RF 2, RF: Guerrilla, and RF: Armageddon. RF 1 and RF: Guerrilla are the best imo.
Indigo Prophecy, a.k.a. Fahrenheit (Xbox, PC) - "Interactive Drama" with a wild story. From the same studio and precursor for Heavy Rain, Beyond: Two Souls, and Detroit: Become Human.
These ate just a couple off the top of my head that I haven't already seen posted here.
SNES era RPGs like Final Fantasy, Lufia, Chrono Trigger, Secret of Mana, Star Ocean, etc. And once you're done, move on to the equally worthy roster of PlayStation 1 era RPGs.
For a Gameboy suggestion, Super Mario Land 2: 6 Golden Coins. This is the first game featuring Wario. You can complete the worlds in any order. When you get a game over you lose all the Golden Coins you've obtained which act.as keys to enter the final world. So you still have to reheat the final stage in each world again if you get a game over. One of the worlds is a giant mechanical Mario you get to go through!
I haven't played this, but the next game in the "series" is Wario Land: Super Mario Land 3 lmao. But I have played Wario Land II. Wario Land II is interesting because you cannot die in the game. Getting hit makes you lose a few coins and that's it. When a boss hits you you get sent back in the stage a bit. Rather than having power ups, some of the enemies affect you. For example, if a bee stings you then you begin to swell up and float. If you're lit on fire then you catch on fire and can burn certain blocks. These are fun because they're oftentimes the only way to progress.
A lot of Gameboy games were kinda crappy. No offense to them or if you liked them, but these two still really hold up. They look and sound amazing. It's a shame to me that so many people seem to remember and are nostalgic for the first Super Mario Land but haven't played the second which is WAY better.
The older Bomberman games, the Metal Slug games from the Neo Geo, Gunbird, King of Fighters 2002, Final Fantasy games like II (PSP is the most complete version), VI and Mystic Quest, コテ・DE・メクール (a PC-98 game), the first Shantae, modern homebrews like Tanglewood, Nyx - The Paradox Relic, Augury Red Code and Micro Mages, Mega Race, Kunio-Tachi no Banka (rebranded as River City Girls 0 in its recent release, and has an option to play with untouched dialogues), Wonder Boy in Monster World, Castlevania: Symphony of the Night, Phoenotopia (Adobe Flash version).
Fatal Frame(s), Silent Hill 1-4, and I agree with the top comment with Katamari. I don't think I've ever frowned playing that game. Also, Sonic the Hedgehog.