Cape Fear (1962)
Robert Mitchum oozes quite menace as he harasses the man (Gregory Peck) responsible for sending him to prison. He makes subtle threats, leers at Peck’s preteen daughter, and always manages to be right around the corner, no matter where the family goes. What makes the film even more sinister is that Mitchum’s character manipulates the law, using it to further his harassment of Peck’s family. Truly one of the greatest Hitchcock films Hitchcock never directed (along with Charade and Les Diaboliques).
Witchfinder General (1968)
This might have made an interesting film, but instead it was content to be a heavy-handed, nihilistic indictment of power in general and the church in particular.