The Exorcist and Alien would be my top 2 I think.
But the one that scared me the most I can't even remember the name of anymore. It was when I was 5 or 6 years old. We went to the Corral drive-in in Calgary and saw this movie that had to do with witches. I remember there was something involving the witches being drowned in the lake and somebody crashed their car into the lake a couple hundred years after and was possessed by the spirit of one of the witches. That's about all I remember of the movie but I clearly remember having nightmares for several weeks after seeing it.
