What are your favorite movies? Why?

I want to know what to watch. I'm bored. I have time to kill. Tell me good movies to watch--the BEST movies, the kind you would watch over and over again. I love all kinds of movies, and I don't really know how to label exactly what I like. One thing I love is period movies--like Marie Antoinette, The Other Boleyn Girl, Braveheart, The Count of Monte Cristo, etc. They don't need to be period movies though. Just tell me your favorite movies and why--is it inspiring, thought-provoking, have intellectual value, is it funny? Things like that. As long as its an awesome movie that you would recommend to a friend, I'm interested in your thoughts. I really appreciate it.