RPGaDay #28 Scariest Game You've Played

I've already told my Ravenloft story, and that's as scary as I get. I've never played a deliberate horror game. I don't own Call of Cthulhu, though I do have a good selection of World of Darkness material. Never played it though.

I tried to run a NWOD mortals game, but it didn't go too well. There was a supernatural element to the game, but it never achieved anything like horror.