I was once watching an interview with Alfred Hitchcock, and the lesson was grand for this thread. he said...you can have some businessmen sitting at a meeting, and a bomb goes off...everyone jumps.
But if you show the audience the bomb beforehand, it builds the suspense, and as it winds down to 1 second, the audience realizes that they aren't going to escape, and in that 1 second, whether they remember it or not, it strikes terror. That terror permeates the subconscious mind, and sets the tone for the entire movie.
Exorcist scared the piss out of me......
Gothica was a great tale...not true horror, even with the ghost...but a grand adventure in suspense...
and of course...the Shining with Jack Nicholson
Mostly, as is obvious, it is the supernatural tales that get to me, i think one of my favorites was Dragonfly, it wasn't horror, but it scared the crap out of me.
In the mouth of madness...for one of those "is this really reality" movies.
and my vote for the worst horror movie ever made......any of the unstoppable slasher movies...except for the first halloween, i like the way Michael Meyers messed with her mnind before coming for her.
If you get the chance, and can get past the religeous foundation, i highly reccommend Bless the Child, with Kim Basinger. A very good movie.