Considering this is supposed to be a children's movie, it's incredibly intelligent. I really loved it. It's all about this girl Chihiro and her parents. They're moving to a new town, and they accidentally stumble into another world. Her parents get turned into pigs, and she has to go along with some of the people and other things that happen in order to save then and help herself. She matures greatly (because she starts out as a very spoiled 10-year-old), and learns some things. She helps some people, and it's a good movie all around.
A wonderfully composed movie about growing up suddenly, in a magical context.