Psycho, I was just a kid and saw it at the drive in, scared the bejeesus out of me.
Exorcist, it made the hairs on the back of my neck stand out. Never since have I had that sensation
Salem's Lot, pretty creepy vampire movie
As strange as it might seem, while Psycho was playing, I was too busy kissing my girlfriend to let it scare me. It did get me tense after I watched it without that distraction.
The Exorcist, I never wanted to see for fear of the supernatural. Some people experienced nervous breakdowns after watching that film.
BTW Jesus is never described as having any difficulties expelling demons. In fact, they panicked when they saw him approach.
Never watched Salem's Lot, but judging by trailer photos, it looks pretty horrifying.