Topic title says it all. What's the scariest video game or video game level? Levels can also be portions of a certain game.
For me, the scariest game would have to be Fatal Frame 2, because getting spooked was mandatory in order to get through the game, and the scares weren't that bad, either.
As for video game levels, I'd have to say the Cradle from Thief: Deadly Shadows is the scariest. The atmosphere was just perfect, especially if you played in the dark in front of a large TV with surround sound.