There are a ton of great horror games, but I'll give some lesser known titles that made an impact on me.

Dollhouse: a film noir, old Hollywood themed constant pursuit game. Very cool soundtrack, and gameplay that's unlike anything I've played. It has an interesting mechanic where you see through your pursuers eyes to locate objectives, but I doing so give away your position. It suffered from development hell and a ten year hype train that ended in review bombing it never recovered from. Give it a chance though, it's great.

Lost in Vivo: a silent hill inspired first person horror game with a lot of clear inspiration and references. You have to save your emotional support corgi who gets washed down a storm drain into sewers full of ghosts and monsters. It doesn't take itself too seriously and has a lot of goofy jokes, but is solidly scary as well. It's made by akuma kira, known for spooky's jumpscare mansion.

Dread X collections: several games comprised of mini projects by students and developers that fit into the horror genre. For a low price you get several games that range from confusing first attempts to unique art projects and solidly fun games. The first few are narrated by the guy from receiver 2, and there's a few szymanski and kira games included. It's been a while since I played through them, but I think 2 was my favorite.

Year walk: a point and click exploration horror based on Scandinavian folklore. Interesting, almost construction paper aesthetic, and lots of good puzzles.

Anyone into horror has to already be aware of RE7, Silent hill, Dead space, outlast, alien, hunt: showdown, and hellblade, but if not, check those out as well.