Alone in the dark 1 made me feel pretty uneasy back when it was new...the sounds, the graphics, the Lovecraftian Atmosphere (back then, I wasn´t aware that it was Lovecraftian sadly). From the beginning with the claw on the window up to...well, 20 minutes later, when I died in the house somewhere...never finished it.
The Shalebridge Cradle level in Thief III. Fucking masterpiece in level/sound design. The other Thief games had some pretty creepy levels, but the cradle was the MOTHERFUCKING SHIT.
System Shock 2. Like Thief, this is mostly because of excellent sound design, and I'm pretty sure a number of the same people worked on both games.
The Clock Tower games. Dunno if anyone mentioned it yet, but there you go.
Hybrid Mode
