I Spit on Your Grave(1978)
Jenny (Camille Keaton, granddaughter of Buster Keaton), a New Yorker who goes to a secluded country retreat to finish work on her novel, is, one day, assaulted, raped and left for dead by four men. But she survives to take revenge. She seduces each of her rapists separately and personally performs their painful executions. This ultraviolent cult film was banned in the UK & Germany and is notorious for many reasons. See it for yourself to find out why.