Suspiria (1977) / Deep Red (1975)
Directed by Dario Argento

WILLIAM FRIEDKIN SAYS: ''Suspiria (pictured, top) [set at a terrorized ballet academy] and Deep Red (pictured, bottom) [set in motion with a murdered psychic] are the most pure horror films on this list. The other films I've named have a lot to say about basic human values, and the things that bring about evil. These two films are just finally tuned machines to scare the hell out of you. And they do. They are the classic blood-spattered slasher films that have been imitated, copied, and remade without credit. They're strictly in the realm of fantasy, but Argento, being the great living master of horror, is so talented that they'll scare anyone who sees them.''