8. Sherlock Jr
Buster Keaton made hundreds of films throughout his career, but Sherlock Jr is one of his best. Keaton is at his most playful, experimenting with the medium of film in new and interesting ways. He plays a shy projectionist who fantasizes about being a great inspector like the one in the film that he's presenting. The stunts and effects used in Sherlock Jr are elegant and complex -- some even required the use of surveyor's equipment, so they could be sure that Keaton and the camera are positioned exactly right to maintain continuity. While the projectionist is dreaming, he manages to walk into the movie screen, making Sherlock Jr one of the first examples of a film within a film. The movie is funny, to be sure, but Keaton also manages a certain tender sweetness between his character and his love interest which makes the film more than just a series of sight gags. It's a tremendously fun film that only runs for about 45 minutes, so it's not a major time commitment for the casual viewer.