"Endless Love", "Eye of the Tiger", "As Time Goes By" - all songs that make you instantly think of the movie for which they're known. "Arthur's Theme" is no different. It is impossible to hear it without thinking of Arthur. In fact, as previously mentioned, it is so good that it won an Oscar.
20. The End
Admit it. You were thrilled when Arthur grew up, Burt Johnson got his comeuppance, Arthur got the girl he loves, and he got the money. Despite the current trend in movies to eschew the "happy ending", you still feel satisfied that Arthur got everything he wanted as the movie comes to a close.