1. Caligula (1979)

Director: Tinto Brass (with additional scenes by Giancarlo Lui and Bob Guccione)

When you make a movie about the sex life of Roman royalty, you have to go big—Roman Empire big. And thankfully, Caligula doesn't disappoint with its sword-and-sandal scandal. Caligula follows a hedonistic man with who takes out the former royalty for the crown, and does just what we would do if we were emperor: throw wild, kinky sex parties. He also does things we wouldn't do (tries to have sex with his sister) and some things we've always wanted to do (have a three-way with a young Helen Mirren).

Under the direction of Penthouse magazine's Bob Guccione, Caligula's already controversial R rated version went way beyond X, with a long, raunchy laundry list that included an orgy with over 50 naked women, several lesbian trysts, fisting, excrement galore, and oral sex, in every possible combination. And if there was any fetish left unexplored, you can probably find it in the 930-minute Imperial Edition, which includes the many sex-tras left on Caligula's cutting room floor.