What is your pick for Scariest Horror Movie ever?

[k55f5r]

33. I went to the neighborhood movie theatre

with some neighborhood boys and saw "The Fly" - the original one 1958. I was 5-6 yrs old and it scared me half to death.
Then, as a teenager, I watched "The Haunting of Hill House" and it was even scarier!
I saw "The Exorcist" the summer after HS graduation...Three people in the front row were laughing every time a new special effect played- pea soup=laughter, head twist=laughter, "your mother in hell"=cackling and snickers.
Due to that, The Exorcist didn't scare me.

p.s. It turned out the people in the front row laughing were friends of mine who had taken windowpane acid and really enjoyed the movie.