Oh yeah, that was a good part too.

The Marine levels in the first AvP used to be unplayable for me. Randomly lit corridors, that goddamn motion scanner and noises of approaching aliens. I was terrified as a kid. Funny enough, that changed after I've played multiplayer with some friends.

Also, each basement visit in Scratches.

Hahaha, that game is horrifying. Especially the Slendermansshadow mods. Still looking out of my window every now and again at night!

Funny, I've heard that same criticism from someone I know. I guess it's not the Doom-style game where you actually shoot and kill what makes you scared, but then again, it was never meant to be like that. The fact that some paranormal element down a corridor or right around a corner can kill you only increases the fear factor. It could also be the difference between terror and horror.

Getting dysentery while making my way west in Oregon Trail ;-)

For me it would have to be psychological horror rather than a horror event or a horror entity.

An event such as a cheap jump-scare. Those just piss me off when they're used. Especially creepers in Minecraft. "Oh, you're not expecting anything, are you? You've checked the area around you? Nothing behind you, you say?" BOOM and at worst I lost a few hours at whatever I was doing, dead or not.

An entity such as a zombie or a vampire. Sure, they're powerful, but in most gaming circumstances, you have the means to defend yourself, guns and weapons. And especially the case of gaming, another chance to 'survive', extra live or a retry. Amnesia: The Dark Descent doesn't fall into this category for the most part. Big, gruly monsters and all you can do is run and cower in fear. ...Unless you're this guy. 'Course, you can always try again from checkpoint if you die.

No, for me, it's the psychological horror that really sticks in my mind. The main one stuck in my head is from Scratches.
[SPOILERS] In the day, there's a door you've been recently able to open. Inside is a trippy African tribal mask. You've read that the previous owner of the house was a collector (IIRC) and took this mask from a tribe. Superstition is on your mind as you go to bed. In the following dream sequence, you decide to check on the mask. You head to the door and notice it's cracked open. You go and look inside the room. The mask is gone and all goes silent. You hear something slammed shut. You turn around. The door is closed. As you open the door, there's this crescending tone playing as the mask 'peeks' in through the crack in the door. Just. Looking. At you. Then the dream ends.

Just typing that last part was freaking me out. It's really the noises that freak me out the most.

Like the poster above me, I don't consider cheap scares to be good horror. It's easy to startle anyone – all you need is a loud, sudden sound; it's a primal instinct. I've been scared by the following games:

Amnesia: because it makes darkness simultaneously your friend and your enemy; because you have no means of defending yourself and the enemies are really disturbing.

Thief 3, the Cradle level: because the ambient, level, enemies and their placement are the most cleverly designed to shred your nerves away.

Realms of the Haunting: mostly the mansion parts, because of the excellent sound design in the early age of gaming, with floors creaking and doors closing behind you; the enemies weren't so scary, though.

Vampire...Bloodlines: the hotel level wasn't so scary, as it relied mostly on "poltergeist" effect (lightbulbs bursting, things flying towards the player), and I soon learned to expect something to happen whenever I entered an unexplored room. There was, however, a single instance when the game genuinely scared me: downstairs in the boiler room, I hid behind a metal tank and saw the killer slowly creeping towards me with a big axe in his hand. I jumped out and prepared to fight him, but there was nothing there!

I know I always say this, but some of you will know what I mean:

"Jesus Christ! Was that a spider!!??"

Snacker, or rather that bloody shark in Banjo-Kazooie. Not only did it scare the crap out of me as a kid, but everyone else I know who played that game as a young-in is the same. I suppose the fact that you have absolutely no defence of any sort, only getting out of the water as quickly as you can, and he's always a little bit faster than you is perfect for triggering one's psychologically embedded sense of "do not want".

Funny how an otherwise very light hearted game does horror far better than many actual horror games.

Condemned: Criminal Origins,

One of my Xbox games and I started playing itand thought this truly is fucked up, I hear Condemned gets much scarier later in the game, with a terrifying final section being hunted by said serial killer in a big house. I wouldn't know because I don't play it anymore. AND YOU CAN'T MAKE ME.

The finale of Condemned is just epic. Anyone who wants to be scared should try it out. That house was really creepy.

Not necessarily all that scary, but incredibly tense and enjoyably challenging:

That bit of Half-Life 2: Episode 1 when Gordon and Alyx have to wait for an elevator to arrive, it's pitch-dark and Zombies are coming in from everywhere.

ooooh, yes, i remember that one !! Scary as hell !!

Oh yes, I'm arachnophobic too. I stopped playing Doom 3 on the level where you first encounter those spider demons. Just quit the game and uninstalled it a couple of days later. Before buying a game, I now usually check whether it contains any spiders and how ugly they are. If it does, I might be able persuaded to play it, but only if I find a detailed enough walkthrough listing every enemy's location, so that I cannot be surprised/jumped by them.

Incidentally, what game has the worst spiders? For me, it's Thief 1. Such an old graphics engine, yet they move in a disturbingly realistic way.

Ocean House Hotel from Vampire: The Masquerade - Bloodlines. One the best, if not the best, scariest level ever made.