Ponyo? I don't know. But I've seen it now and I loved it.
This is Miyazaki's interpretation of Hans Christian Andersen's The Little Mermaid. Not a direct version, but a Ghibli take of the tale. Ponyo is a little magical goldfish that stumbles into the human world and wants to live there. She is very young, yet extremely powerful. Her naiveté and her determination prove to be very trecherous for the people who live in the island community where Sosuke meets Ponyo. Like almost all of the Ghibli films, there are no antagonists in the story. There is conflict, but all of it is really people versus Ponyo's inadvertent effect on nature.