Clive Barker's Undying carries the distinction as one of the first games to carve an expression of terrified horror in my face from start to end. I swore I'd never revisit it, but it's on GOG now for $6, an absolute steal for one of the best and truly frightful first-person survival horror games out there.
As with the rest of GOG's library, Undying's olden 2001 graphics are kept pristine while taking a bump in compatibility for Windows XP, 7, and 8. For more nostalgic incoherent screaming, here's the intro trailer.
