[Mad Melvin]

The monsters in Amnesia: The Dark Descent. Even though the monster design isn't that original, the atmosphere of the game make up for it and they become a thing to avoid.

The monsters in Silent Hill 2 you cannot see. For example, the underground prison scared the piss out of me. There is a cellblock where you hear this really freaky sounding monster waltzing around in one of the cells. It is too dark to see it and it can't hurt you, but I always ran through that corridor as fast as I could so I wouldn't have to listen to the sounds. Also in the beginning of the game when you walk on the dirt road, you hear footsteps behind you. That always made me feel uneasy.