My favourite generation is the one I have nostalgia for and the first one i played, Gen 3
Ruby and Sapphire i think had really good pokemon designs especially my favourite legendary Groudon, he looked metal as fuck on my copy of Ruby. I enjoyed the soundtrack from the GBA version and matched the anime based from it, Pokemon Advance.
What is your favourite generation and why? What details makes it stand out for you?
Gen 2, Crystal. Was my favourite. I found the character selection and graphical upgrade was really nice. Gen 2 includes the previous game world. Collecting all the badges again was special.
But I played Gen 1, Blue the most. The missingno trick was a bunch of fun and it was my first gameboy game.
Edit: my friend said Soul Silver is peak and sun/moon is a close 2nd place.
My nostalgia goggles tinting things a bit here, but Gen 2 (GSC) felt like such a jump in quality compared to RBY; especially Crystal.
Moved to full color
Animated sprites
Character selection
RTC & the day-night cycle
Both regions & 16 badges
QOL mechanics (hold items, eggs/breeding, A to use HM, rematches, Mom bank, Move Deleter)
Dark & Steel type additions
Johto gets a lot of flak for the level curve, but the game just felt so big at the time, seems like that should count for something. Also I just like its vibe.
I don't think any other gens have felt like such a complete step up compared to previous ones for me. B&W came closest, probably, was bummed they didn't keep seasons. Made the world feel more dynamic. The 3D stuff is fine, just feels more wooden. They lost a lot of the charm moving away from pixel art.
Gen 4 or Gen 5. so much post-elite-4 content, and it's not just "grind this arena endlessly" post-game content. Actual adventures in the case of the Gen 2 remakes and Gen 5.
Gen 3 holds a special place in my heart (Emerald was my first pokemon game) but the creature comforts of gameplay in 4 and 5 hold up a lot better
I enjoyed the gen4 remake for switch but it seriously lacked the amount of content in Platinum. They had a chance to greatly expand the distortion world and just... skipped it entirely instead.
Whichever generation was in the Pokémon game for the original Gameboy color. The one where there was a red, green, and yellow version of the same game.
That's the only real relationship I have with pokemon, because it was such a great game. So great that I loved the game and played it on an emulator, as I didn't have a Gameboy.
I tried later games and I just can't. I find the pokemon designs beyond Gen 1 to be really rough more often than not. I'll admit that gen 1 isn't immaculate but they're much better than what looks like a dog rolled around in random Gundam parts.
Gotta be Black/White. It was the first time the writing really took a step forward. The antagonist wasn't just evil for no reason. They had a compelling story and their motivations made sense and you could sympathize with them.
Five, because it was the only time the series innovated, and they got punished for it. Sequel games instead of re-releases of games I've already played, a brave story, and easily the series' musical peak. It was the best Pokemon had ever looked, played and sounded.
Pokémon Generation 1 and 2. They story, gameplay, and mechanics are concise and not hand-hold-y, the designs are the ones I grew up with, they can easily be played on a phone emulator and have so many rom hacks that I never will totally experience everything they have to offer
If I'm answering the question as given, Gen 2 because it was the first games I owned, so that's certainly nostalgia speaking. However, over the years it's just so obvious that Nintendo/Gamefreak refused to evolve the series and the variants of the genre are the better games.
Gen 1 had a lot of design issues: The special stat is overpowered, too many pokemon were poison type, move diversity was so poor that some types were just useless, and there were a lot of glitches.
Recent generations also have design issues: The story holds your hand every step of the way, characters are more detailed but less expressive, each generation has a gimmick that gets abandoned in the very next game, and there's somehow a lot of glitches again!
Personally, my sweet spot is gen 4, but gens 3 and 5 are pretty solid too.
I think two for me. In my opinion, it had the best animated sprites (later animated sprites were sometimes the entire sprite bouncing which felt lazy to me). I stopped playing after gen four though, so I'm definitely missing some.
Also nostalgia answer but i loved gen 6, Y was my first game. Mega evolution was rad as hell and getting mewtwo from the movie was awesome.
But the delta episode of Alpha Sapphire made AS my favourite, the idea of a whole nother timeline connecting it back to the older games blew my little mind.
Then they didn't do mega evolution in the next gen and I stopped playing
Probably Gen 2 because PKMN Soul Silver was my actual first game (I lated had a Gold GBA cartridge) and gen 4 because it has the best story (plus Giratina and Dialga are my favorites besides Lugia)