3. Eternal Sunshine of the Spotless Mind

You should only watch this one if you want to be sort of depressed. Actually, it's also a good pick if you'd really like to forget about your recently departed relationship. It shows that forgetting is never the answer, because there are things you have to remember – and things you simply can't forget. You can, however, come to terms with them, learn to live with them, and feel better as they gradually turn into memories that aren't quite so fresh and painful.