1. The Exorcist (obviously…none has been its equal…nor do I believe any will be).
2. ALIEN
3. Carrie
4. Exorcist III (Agreed, it is more like a crime drama, but it was good seeing George C. Scott in the role originally intended for him, and the return of Jason Miller. And Brad Dourif did a great job as the Gemini Killer's spirit.)
5. The Omen (both versions)