My favorites are:
Halloween Series
Stigmata
Scream 1
The Blair Witch Project (Yes I know, but try watching it at midnight, when you're the only one in your house cuz your roommate is gone like ALL of your neighbors on spring break, and no one is around........this was the second time I saw this movie other than "at the movies" I kept hearing noises outside I swear and I didnt sleep all night)
None of these movies I'll watch alone