This is very tricky for me, as although I consider myself a film enthusiast, compared to many here and of my other film loving friends my experience with horror is meagre in comparison. Here is my rough list anyway.
1.
The Thing (1982)
2.
The Exorcist (1973)
3.
Videodrome (1983)
4.
Cannibal Holocaust (1980)
5.
Alien (1979)
6.
Black Christmas (1974)
7.
The Keep (1983) - if you count it as horror, which I know some may not.
8.
Suspiria/Deep Red (1977/75)
9.
The Beyond (1981)
10.
Halloween/The Burning (1978/81)
Again my exposure to horror as a genre is still rather limited.
