Diabolique (1955)
Directed by Henri-Georges Clouzot

WILLIAM FRIEDKIN SAYS: ''This film was remade years later with Sharon Stone — forget that. The original, which is a French film, is filled with surprises. A man runs a school with his wife, and one of the teachers is his mistress. The two women decide that this man is so brutal to both of them, that they're gonna kill him. They attempt to [hide] his body and along the way, little hints of evidence show that he is perhaps not really dead. Or that he has come back to haunt these women for what they've done. You're never quite sure. It's totally realistic, and has the biggest surprise at the end of any of these films. It's a wonderful conceit, brilliantly realized.''