I love horror but apparently I don't vibe with a lot of recommendations I find online.
I'd seen so much hype about Event Horizon and I absolutely hated it and didn't find it scary. I just watched Late Night With the Devil and whole it was definitely enjoyable, it wasn't the least but frightening. I also just watched Let the Right One In and really didn't like it. It also was not a horror movie in my opinion.
I will say one of my favorites is Sinister or the first Conjuring. Sinister for the stomach twisting dread and suspence throughout and Conjuring for the same.
It Follows. It isn’t the best horror movie, but the premise is one of the scariest for me. An entity that is inevitable, and you cannot get away from no matter what you do or where you go. It’s always there, walking towards you.
There is a particular type of emotion which "The VVitch" and "Hereditary" get absolutely perfect. It's actually not really my favorite type of movie; it's not particular scary, per se, but it is just some stuff that is really awful that you don't want to see. If you don't want that, they may not be good, but if you vibe with that particular emotion they are hard to beat for it.
The HBO "Chernobyl" miniseries is absolutely straight-up horror. It has pretty much all the elements of a perfect horror movie, except it's (with tiny exceptions and artistic licenses) all 100% true.
"As Above, So Below" is fairly good "normal" horror of a fairly unspicy flavor.
That's honestly all I can think of that really does it well. Horror books in my experience are far better. "The Shining," "Pet Semetary," "Night Shift," and "Skeleton Crew." Also lots and lots of HP Lovecraft; the "Dunwich Horror" collection is wonderful.
I don’t consider many horror movies genuinely scary. The ones I have, at various times in my life, been actually in some way frightened (or at least shook) by, in no particular order:
The Exorcist (The Version You’ve Never Seen)
Hereditary (a masterpiece in my opinion. Free upvote literally every time I see someone recommend it)
Blair Witch Project
Paranormal Activity
Ouija: Origin of Evil
It (miniseries got me as a kid but Chapter 1 is good too)
Lights Out (not the entire movie but it has its moments and overall a good style)
Candyman (original)
Poltergeist (original)
Autopsy of Jane Doe (another poster reminded me of this one!)
The Taking of Deborah Logan (for like one scene but IYKYK)
The Dark and the Wicked
The Orphanage
Terrified and When Evil Lurks were both solidly unsettling at least
Event Horizon (though I know you didn’t like this one)
Conjuring 1-2 and Sinister too, all at least solid spookies.
Note that this does not mean these are the only GOOD horror movies. There are LOTS that I consider masterpieces that just aren’t strictly all that scary.
Everything about it is excellent and holds up even now. The musical score is exceptional.
Don't bother with the reboot. It has a message it's trying to send, which I get, but they've done it to the detriment of the horror. Something could've been done with the premise but they fell short.
I’m pretty dead inside so not a ton can get through in the horror department, but I always thought 28 Days Later and 28 Weeks Later did a fantastic job making zombies a bit scary again.
If you want something a bit different, seek out Threads. It's on the Internet Archive (here, in fact)
Not a traditional horror film at all, it's set in the north of England in the early 80s (depending what n where you're from, the accents might prove a challenge!) and shows the ordinary people of a small city gradually coming to terms with escalating tensions between East and West, which result in all out nuclear war.
And then we get to see the actual on the ground nightmare that that would be. Not in a showy Hollywood way but in a grim, horrifyingly real feeling gritty British drama way. Bleak isn't the word.
It's something that's never quite left me since I saw it for the first and so far only time some years ago. Truly disturbing, and not fun at any point after things start getting serious. Brilliant though.
For me The Shining is one of the scariest movies and The VVITCH also comes really close to that feeling. For different types of horror I'd also recommend La Piel que Habito, Shutter and The Haunting of Hill House (the show).
And if you get the chance try the book version of Let the Right One In. It's much better than the movie and more of a horror imo.
I absolutely love and hate how they mess with your perception of not only time but what's real because I could see myself in situations where I couldn't tell you how long has passed and/or having to question if what I'm seeing is real or not.
Some suggestions from my side - in addition to many already posted suggestions I would add to my list as well:
The series Twin Peaks (all three seasons plus the feature 'Fire Walk With Me') is not 100 % horror but it has it's tense of mystery and some scary scenes as well
Don't Look Now from 1974 - a classic mystery drama with great Donald Sutherland in the leading role - also more mystery/suspense than horror
IT (reboot) - still scarier than the Terrifier movies which are more slasher / fun-splatter
Quarantine - until I saw the original 'REC'
Schock - Italian horror movie classic
Barbarian - I expected different but I was surprised in a positive way
Many other good ones have already been mentioned, so I won't repeat those titles. But "Suspiria" (2018 edition) definitely deserves a mention. The ending is just ... well, clearly somebody amongst the original writers had some issues regarding reproductive systems ... but the other 98% of the movie feature brilliant suspense & eiriness at all times. And Tilda Swinton is simply to-die-for in it. ;)
I absolutely love horror movies and have a long list of fantastic ones but not very many of them actually scared me. Most of them have been named already but two I didn't see were The Babadook (2014) and surprisingly a Netflix movie called His House (2020) was actually awesome. One of my favorites in the last few years.
I don't get scared easily, but Kothanodi had me watching through my fingers. It has four vaguely connected stories, and two of them are very fucked up. There's a decent amount of infanticide and other atrocities inflicted on minors, so be warned if you have any childhood trauma.
Also by the same director, the movie Aamis is about cannibalism acting as a replacement for sex. It's pretty fucked up as well.
so many recommendations already said and im sure many more to go.
Three that i didnt see mentioned that i enjoyed were:
Martyrs- French Version
The Visit
Session 9
Scenes from martyrs have been memed out of context so i think its fairly familiar. i hadnt watched it until recently and i think one time through was good enough for me. i’m not into a lot of torture style suspense.
The visit was particularly scary for me because If you’ve ever been in that scenario of being dropped off with familial strangers those initial reservations you have running through your head do make you uncomfortable and blossom into horrific thoughts. in the case of this movie a bit more so ;)
Session 9 i watched during the golden age of netflix. it isnt amazing but it was enjoyable.
What I've learned from this thread as someone getting into horror again is that I really need to watch Hereditary and the original Candyman. Might just bookmark this for all the great recommendations. Only hard part is that my partner isn't into horror so it's hard to watch them.
The Borderlands (2013) is a great found footage horror film with a unique twist on the genre. The ending was particularly horrifying to watch, and I don't normally find horror films scary.
Talk To Me. I would also say Sinister and The Conjuring are my favorites, and I also struggle to find scary movies that genuinely scare me. Watch this alone in the dark the first time. It is now my all-time favorite scary movie, and it's fairly recent.
I'm noticing a distinct lack of Terrifier and Terrifier 2 in these comments. Art the Clown is perhaps the best antagonist I've ever seen in the horror genre and true originality is rare in the modern horror filmscape.
The Ring is also good for originality as far as modern classics, though it's a whole book series in Japan.
Edit: I also liked The Shrine, forgot to mention that one. Again, originality.
Megan is Missing (2011) is one of the most horrifying films I've ever seen. Fair warning though, the last ten minutes are excruciatingly painful to watch. It is not for the faint of heart.
In the gore porn genre Cannibal Holocaust (1980) and Hostel (2005) are vile, but so pointlessly gorey the actual horror (the brutality of men) is almost entirely lost.
Funny Games (1997), or the 2007 American remake for those who don't love subtitles, is another unnerving portrayal of ultra violence. It's not gore porn, but is graphic. The original version's pacing will make you squirm in your seat.
Hush (2016) and Creep (2014) are two of my movie-night-with-friends films. Still very much about the human monster, but not overly graphic and prefers to build by making the viewer a partial participant. You have to be a certain level of broken to enjoy some of the others on my list, but these two are disney movies compared to Cannibal Holocaust.
"Ju-On: The Grudge" from 2002 was probably one of the scariest movies I've seen (if you don't mind reading subtitles). The US remake did not do it justice IMO.
I don't know how well it holds up nowadays since it's so old and I was a lot younger when it came out.