I love all zombie movies and all the evil dead movies (second one was freaking hilarious, especially that eyeball flying through the air
)
But when the exorcist first came out, I remember going to the drive in with my parents and the whole bed jumping scene...... to this day it still scares the shit out of me, figuratively of course.
The shining and the original Hellraiser have to take honorable mentions.
Rosemary's baby and It's Alive (that monster baby movie. Although not at all scary by todays standards. That whole creepy baby monster hand hanging out of the basinette thing scared me. Again I was a little kid) also creeped my out
Todays movies aren't really scary just creepy, gory, and make you jump. Maybe because most it has been played out or I'm just older and have seen most of the "scary" stuff out there.