Metro 2033: The Library
a.k.a.: Staring Contest nationals
I called bullshit on that one
until the black one popped out, then I was like: really, guys?
then I went to the "sewers", man I can't even begin to tell you the amount of times I tripped over those fucking sleeping librarians, even with my night goggles on I tripped over them
well, that and stepping on the ribcages
edit: oh, I almost forgot, the cave in Ultima 7 (or the Forge of Virtue pack, don't remember properly), where them crazy fucks sacrificed people and shit
and that baby on the table thing, all dead and shit =P
of course, it was back in the day when it happened, so, yeah, I was, uh, "weaker" then
and let's not forget the UAC Station in Doom 64
I swear that's the most atmospheric game and overall scariest space station thing, of course, until System Shock 2 came out