I got a list of scary games.
Clock Tower (SNES): The suspence can kill a person on this game... I hope it DOESN'T last, cuz it's... wow. Just try it. Only problem is it's too short. (you can beat it in 10 minutes if you do it right)
Abuse (DOS): There's no music to this game for a reason. You can be walking along, all normal, just an average corridor, then BAM! 50 ant enemies (not insects, FAR scarier) right surrounding you. Nothing to do but pull out the rocket laucher...
Descent (DOS): Hey, SHUT UP! If you're playing this late at night, it can give you quite a workout for the heart. (Diamond Clawbots.... Holy spit....)
Doom (DOS): Of course, GOTTA put this on the list. I haven't played Doom 3, but the old one can be just as bad. Damn, the first time I played this, at night.... Speakers loud... All alone.... Nothing but a pitol and shotgun.... Damn, I got the freaks....
Wolfenstein 3D (DOS, of course): if you can get past the archaic graphics (who can't?) This game gives you a good scare. Turna corner, BAM! Nazi right in your face. Scares the living daylights outta ya....