Casablanca, it's probably one of your two or three favorites. If you've never watched it, shame on you. There are very few movies that can be involved in a "best movie ever" argument. Sure, you can argue that the original Halloween is the best horror movie of all time and you can argue that the original Arthur is the greatest comedy of all time. You can even mistakenly argue that Butch Cassidy and the Sundance Kid is the greatest western of all time. But none of those can compare to Casablanca in a "best movie ever" discussion. So here are 12 reasons why Casablanca is OBVIOUSLY the greatest movie of all time. In fact, Casablanca occupies the top three spots in the greatest movies of all time - that's how great it is.