Obama, but he reads creepypastas:
Get no sleep here
Rules:
My vote goes for Tomb Raider II and the floating islands levels. The game is a relativity normal globe trotting affair for Lara until she gets transported into the fucking shadow realm here. This level gave me major scares as a kid since you're traversing a giant void being chased by animated statue warriors out to kill you.
I think Outer Wilds qualifies, when you encounter a certain giant creature the very first time
Outer Wilds is cosmic horror in the original sense, you're forced to grapple with the fact that you're a tiny meat creature in a universe that keeps moving even if you're in the way.
Night in the Woods.
Yet to play it.
The Shalebridge Cradle in Thief: Deadly Shadows is to this day one of the most unexpectedly pants-shittingly frightening sequences I've experienced in a game.
on that note don't know if VTMB counts as a horror game, but goddamn that hotel level fucks with me no matter how much i know that i'm supposed to be the scary thing in the dark 
it is impressive that they managed to give people playing as immortal creatures of the night the willies
"I'm a big bad vampire, you cant fucking scare me, ghost."
lightbulb blows up
"oh god please no i'm sorry"
*barely dramatised version of me playing through it for the first time
Gone Home.
at times it can be pretty creepy. but that game had me bawling like a baby at the end
My submission would be Legend of Legaia, its an old JRPG with some fighting game inspirations that has some really bleak levels in it. For instance a city where the residents have been consumed and fused with an enormous monster, so you find them as these like fleshy statue growths that are still aware of their situation, but powerless to escape it
Legend of Legaia
I had a demo for this one I think growing up and I never got to play the full game. That's pretty messed up.
I honestly found all of the first 3 lara games scary. Something about the lack of music and echoing footsteps. I always felt like something was constantly sneaking up behind me.
Yeah very unnerving games at times.
Metro games are a good mix of action with a dose of horror/existential dread
Been ages since I played Metro, I remember liking the first one.
Metro last light is even better. Highly recommend giving it a whirl, the story is much more engaging.
That bigass eel in Mario 64 he's gonna jump out and bite me
The panic sound when Sonic's drowning 
exactly 
Also any level with lots of "masher" obstacles
How about GMOD, or Half-Life 2 anyways? I've heard they're good...
Norco. Really cool point & click with a just a few super creepy scenes, but the whole thing is very atmospheric and moody
Max Payne 1
Max Payne 1
Oh good pick, I remember some of the creepy scenes in that.
The deeps in TOTK
Lavender Town has no business being that creepy.
Arkham Asylum, especially the Scarecrow scenes.
That one dark semi underwater level in the last of us part 1. The one where you have to get the key to start the generator, with the stalkers I think. Really took me by surprise on my first playthrough 8 years ago with how creepy and left of field it was for a zombie game. I did it stealthily as well, which added to the creepy factor.
ooooo the first uncharted was terrifying the first time you find the zombie conquistador monsters
The sewers in Shadows Of The Empire. Opaque water, foggy map, and an enemy you could hear long before it got to you but had no idea where it was coming from.
I have no idea what the monster even looked like beyond that it had tentacles.
Also:
That piano
I don't even need to say the game.
That piano
I don't even need to say the game.
Mario 64?
LSD Dream Emulator
Great game!
The Marathon trilogy, a 90s bungie FPS with, notably for its time, a story. Bizarre, frightening creatures sneaking up on you throughout, in dark spaceship corridors and ruined alien castles. It has clear inspiration from the movie Alien, but plays more as action/puzzle than survival horror.
Kind of an obvious / lame answer but I always enjoyed playing Minecraft with my friend back in the day, it'd be just the two of us with no monsters but we'd still hear ambient noises and get creeped out.
~~There's also horror in Kor, if you know how to find any / all of the three easter eggs~~
Some of the ambience in City Skylines sounded like Amnesia music and it actually spooked me out of playing it 
On both versions of Shrek 1 you can get out of bounds on most levels and fall into a void. On the Xbox version you fall into a sort of chicken purgatory that you could only exit by turning off your console. During the credits there is artwork of the main bad guy flying with chickens and there is also a cheat about him that may or may not do anything. This has kept me up at night for two decades.
Well now we are all cursed so thanks
Metroid: Fusion, before you've regained your power and just have to run from the X... same feeling with the EMMIs in Dread.
Pokemon S&M and its Ultra spinoffs did some solid horror. Though Digimon Cybersleuth really leaned into it with Ghost Floors and organ harvesting.
Timesplitters
KOTOR shark level. KOTOR shark level.
Halo 1's flood level
Timeless classic