There's a lot of films that have truly scared me over the years. I'm quite glad to see Worthy provide Halloween as one of the essential horror films.
For me there's a vast amount of horror films that have made me quite uneasy, whereas even to this very day I still get creeped out.
The original Amityville Horror scared me so bad that I slept with the lights on(no lie) for the next two days. Everything about it was perfect with its subtle use of sounds, images, and atmosphere aspects that put the viewer on such a edge that it left me feeling cold. The scene with the priest being attacked by the flies along with the voice telling him to "Get Out" is creepy.
The first Nightmare on Elm Street comes to mind too. Freddy's introduction with the way his arms stretched out and the way he chased his victims made me shudder.
I'm sure others will disagree with me on this notion, however, I have to say the first Final Destination was very good and a great original concept. That film made me very paranoid afterwards.
But for the rest of the scariest films of all time here is my list:
1. Amityville Horror/Nightmare on Elm Street(tie)
2. Halloween
3. The Exorcist
4. Psycho
5. Audition
6. Black Christmas(Original)
7. When A Stranger Calls(Original)
8. Phantasm
9. Hellraiser
10. Rosemary's Baby
11. The Omen
12. Blair Witch Project
13. Texas Chainsaw Massacre(Original)
14. Pumpkinhead
15. Poltergeist
16. Misery