The video game moment that scared me the most was in the first Condemned for 360.
MINOR SPOILERS:
Your in a school and looking for a teacher that you think has been murdered. Eventually you find his mutilated carcass stuffed in a locker - his lips ripped off...nasty...
So the woman at hq asks you to take a close up of his face for evidence. You have to manually zoom the camera ALL THE WAY IN to his face, then
BOOM!! The supposed cadaver is yelling at you through a lipless mouth. I don't know how I didn't see it coming, but it got me so good...
The best has to be that insanity in Eternal Darkness where it says "Controller 1 disconnected" right when you find yourself being attacked That game was so awesome and original. I'd love to see a game like L4D2 with some insanity effects
Playing RE2 and some birds busted through some windows I was running by out of no where. Scared the crap out of me.
Mine is very similar, I was playing RE2 late one night and really absorbed into the game. I think I had just finished the area with the birds breaking through the windows, or maybe it just feels like it, because a giant frickin' owl came smashing through the window. I just about shat myself it was so terrifying.
There have been many over the years, most with headphones on. I think my latest was the worst. I was playing Left 4 Dead (in the dark, with headphones on, late one night). A boomer threw up on me. I couldn't see because that green crap is all over the screen, so I am using the melee weapon - doing my best to bat the horde off me, when my father shakes my shoulder with his bony hand to tell me to go to bed. It freaked me out so bad I had to turn the game off
Working for Looking Glass Studios and playing an early build of System Shock 2 in an empty office on a sunny afternoon with my back to the door. Someone stuck there head in and I literally screamed like a little girl. Led to a day spent rearranging my broom closet/office so I could see the door while I played. I think I may have wet myself. Oh, and the mirror scene in Doom3 at 1am in my basement made never play that game in the dark again.
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"God Was My Co-Pilot, but we crashed in the mountains and I had to eat him." - Unknown
Definitely the first F.E.A.R. game. I got so freaked out many times during that game, but spefically one place keeps scaring me time and time again.
You are walking in an empty, dark office building (duh) with alot of cubicals. I had just beaten those darn invisible thingies and I proceed forward when my light starts flickering. I turn a corner and from a completely dark cubical Alma comes crawling at top speed right towards me. I freaked so much I emptied my clip in the dark cubical, pushed escape, rolled back from the desk and just froze.
And at that same time my big brother turned on the TV (which I now sat right next to) and scared the living shit put of my. I was sure the little girl from The Ring (Tabitha?) had teamed up with Alma to kill me. Jesus I was scared.
while playing battlefield 1 (yes, i know freaky!) late one night during a rain storm I nearly fell out of my chair when my house shook and the lights flickered almost in time with my position being bombed. Suddenly the power went out.
Come to find out the tree outside got hit by lightning and jumped to my house.
I played F.E.A.R. backstage during a production of Hamlet I was in (it's a long play -- I had an hour during the show where I sat backstage waiting for my next entrance). One of the other cast members was watching over my shoulder one night. I climbed a ladder and there was Alma at the top -- I jumped, he totally freaked. I had to grab him and cover his mouth so the people watching Hamlet wouldn't hear a scream from backstage.
That game was so awesome and original. I'd love to see a game like L4D2 with some insanity effects 
