The first Resident Evil movie. Not because of the zombies, it was the laser scene that got to me. I was convinced that lasers would come out of any reflective surface to get me. I didn't like how they seemed to react to the guy avoiding them, making it impossible for him to escape, like they were intelligent and trying to kill him.
That and some other horror movies i really liked, like ghost ship that had an into scene where a bunch of people got sliced up by a quick moving wire. Then there was what, cabin fever?