I have to say Dead Space, had a few light strokes because of that game.

Dead Space was pretty scary, I think Condemned has a few more scary moments though.

Condemned, but I've seen a few scary moments watching my cousin play Dead Space.

Siren blood curse.

bioshock

Condemned!

Tough call between Siren and Condemned.

BioShock's atmosphere gets an honorable mention, though.

Hmm staying away from Condemned

Dead Space was amazingly tense, especially the vacuum parts where you couldn't hear anything. I almost wet myself each time some creep managed to sneak up on me.

Condemned gets the prize, though. It left me feeling really scuzzy... I had to take a shower after that one.

I would also like to point out how much it freaks me out in oblivion when I'm in a cave and my torch goes out right when a zombie is groaning it's way towards me. The music in the caves is seriously haunting in that game.