The first time I played the Ravenholm level of Half-Life 2, I was almost too scared to even start it. There was this one bit in particular where I killed a bunch of zombies, turned into an alley to look for supplies, and a headcrab that I thought had also been killed jumped at me. Practically made me jump out of my skin.
Also, in Fallout 3, any time where I'm walking around the Wasteland at night is usually pretty unnerving, especially at the higher levels, where a deathclaw could very well jump at me from behind at any moment.
Also, in Fallout 3, any time where I'm walking around the Wasteland at night is usually pretty unnerving, especially at the higher levels, where a deathclaw could very well jump at me from behind at any moment.