I'm going to have to go with the original TV Salem's Lot. I was younger then (shocker, I know!) and some of the scenes still stick with me.
Though the one that haunts me the most is not even scary by itself. The scene when the guy was in the cemetery all by himself, and the wind starts blowing. The next day I'm outside playing on a friend's swing/gym set by myself. The wind picks up hard out of nowhere, and I realize I haven't seen a single person or heard a car since I came out of my house 1/2 hour ago.
I freaked. Those 2 are linked forever in my mind, and I can still get antsy if I'm all alone outside and there is a strong wind blowing. Nifty, huh?