f.e.a.r. My god, countless scares in that game,countless. The famous ladder,elevator and a few other scares. :S!
f.e.a.r 2 demo also scared me shitless
Bioshock's atmosphere ftw (Y) the dark room with bastards running at you <3

Fatal frame is also one hell of a game, i just wanna talk about it. :D Im alone and its dark here. :(