Another vote for the original The Haunting.
You can add:
The Magician by Ingmar Bergman... the scene in the attic doing the
    autopsy scared the Hell out of me
Night of The Hunter is on my list
Dead of Night gave me the Willies
Carnival of Souls, for a cheapie movie still gives me the creeps.
The Innocents with Deborah Kerr (not the Innocent Wannabee, The
    Others with Nicole Kidman

If you want to scare the Hell out of yourself, play the Playstation 2 games of Silent Hill.

Jerry