The Exorcist/Nightmare Fuel

The Exorcist
"Homeless Man: Father, can you help an old Altar Boy. I'm a Catholic."
 * Let's just start with the idea of your 12 year old daughter being possessed by a demon and stabbing herself in the crotch with a crucifix.
 * Don't forget the several flash frames of an insanely evil-looking demonic face.
 * Even the screen tests for the make-up are unnerving....
 * There was one scene that didn't initially involve the demon at all, but was still unnerving. Damien is taking a Subway to visit his mother. While he waits for the train, he is briefly accosted by a homeless man asking for change. While the scene doesn't seem to go anywhere, when he meets the possessed Reagan, the Demon briefly imitates the homeless man to freak him out.