Actually I downloaded the Fear expansion demo the other day and there's a short section there that gave me the willies.
You enter a series of rooms in that are in disarray, junk everywhere, scary music and there's these semi-transparent things (with glowing red eyes) that come at you from the darkness, punch you, deal heavy damage and then scamper off before you know what's happening. Your bullets don't hurt them - you have to punch them back to kill them. Don't know why, but it really gives me a fright.
You enter a series of rooms in that are in disarray, junk everywhere, scary music and there's these semi-transparent things (with glowing red eyes) that come at you from the darkness, punch you, deal heavy damage and then scamper off before you know what's happening. Your bullets don't hurt them - you have to punch them back to kill them. Don't know why, but it really gives me a fright.