'The Godfather' Trilogy (1972-1990)
If you haven't seen The Godfather, you should be ashamed of yourself. No, but really, if you haven't seen all three dark and theatrical films of the Italian-American mafia trilogy, go watch them all, right now. You will immediately be sucked into the powerful, mob-centric family drama. Plus, these classic Francis Ford Coppola Films have got Marlon Brando, Robert DeNiro, and Al Pacino? C'mon.