It was the atmosphere of Burnt Offerings that got me... first movie in a long time that gave me the creeps. Plus I like the actors. This guy is all wrong!!!!!
Has anyone mentioned "Nightmare"? I thought it was creepy, especially at the end when he is wearing the mask. It's pretty obscure but good imo.
Reminded me of Maniac. I was on a "The Burning" kick a while back as well.
"The Brood" has been mentioned and is very scary and intelligent.