Corpse Party for PSP. I developed a fear of dying in the game since I'd be seeing a 2 - 20 minute scene of the person or the people dying... Grotesque or mind breaking way.

Second would be Amnesia: The Dark Descent, but only because I watched Let's Plays before playing it, reason being that my current computer couldn't play it. When I got to play it I wasn't nearly as scared as I should've been.
But there was some moments where I couldn't remember exactly what's happening, like in the prison. I heard a grunt's voice, rushed into a prison room and shortly found out that the grunt was in the very same room. Couldn't escape in time.
also the moment where the brute had to be distracted so that I could go past it. the adrenaline

Well, it had its scary moments but also quite a lot of horrible deaths... I'll have to vote for Demonophobia.
It's a guro/ryona game about a little girl who accidentally summons a demon whilst taking an ancient tome as a joke, and ends up getting sucked into hell or somesuch place where she gets killed by just about everything, only to be put back together again every time until she manages to make it through.

Also, Resident Evil 3: Nemesis scared the fuck out of me whenever Nemesis showed up because I was young and hadn't figured out how to break free from grabs yet (failure = horrid low-resolution death) and was smashing the awkward controls to try and run the fuck away. Even worse if I ran out of ammunition/had a shitty gun/no weapon at all.

"S.T.A.R.S."

gotta agree on this one, some of the death scenes were a bit... well scary.

mario kart. Its scary when they pass you at the last second.

the white chamber would have been scary, but it wasn't. The Chzo Mythos too, but instead of scaring me, it did nothing.
In fact...
The only scariest game I have ever played was Dragon Age: Origins, but only for six months. Now it's not scary. And I'm 16.
Before I was 12, it was Grandia 2 (PC). What kind of Б9-year old would want to fight flying eyeballs?

probably amnesia : the dark descent...damn creepy

and f.e.a.r the first one xD
the 2 sucks and didnt play the 3 yet

Doom' on the xbox shit was crazy when it first came out.
Also the older resident evil games scary as hell.

F.E.A.R. became less and less scary as the series went. You just kept knowing what to expect. All through the game, mostly all scares are jump scares. A girl appears, some monsters around, poof, she's gone, you shoot the hell out them.

Or probably just the girl appears and/or an image of a bloody man on your screen for less than a second. All of them are jump scares, and frankly, there comes a time where you know when to expect those.

They used those kind of scares so much, that every time I enter a room, I know that either the girl is gonna pass from a side of the room to the other, or appear at the end of the corridor, or probably just charge towards me.

In amnesia, the atmosphere is what gets you, plus, you can't defend yourself. All you can do is either run or hide, not shoot the crap out of the grunt/brute when they appear, that's what makes it scary. And remember, the scary atmosphere is what qualifies a game as horror, not a non-stop amount of "BOO! *shoot!!*".

It was minesweeper.

Hotel 626
Its free, search it up.
damn i hate the nurse.
there was this guy tied up on a chair, you cant see his face.
you'll do something then if you get it right/wrong, the guy will suddenly stand up, free from the restraints, then he comes closer to you, then the last one was he scares the shit out of you (long time since i played it)
and you die automatically at 6 o'clock...i mean, srsly? dafuq?
and the baby scene...
Shit,why did i have to see this thread and re-experience my sleepless nights? (haven't slept for a week after the game)