Classic Movie Scripts is a site that hosts a long lists of, unsurprisingly: movie scripts. The list isn't very long but keep it in mind, it might grow. I was happy to find the script to Annie Hall by Woody Allen. One of my favourite films of all times. This is taken from Annie Halle:
ALVY Tsch, I know. A relationship, I think, is-is like a shark, you know? It has to constantly move forward or it dies. (He sighs) And I think what we got on our hands (Clearing his throat) is a dead shark.