
I am a huge fan of Hayao Miyazaki's work (the writer and director), but I was severly disappointed by Ponyo. It was incredibly cute and touching, but it felt more hollow than anything I'd ever seen Miyazaki do. It was basically a weird, Japanese adaption of The Little Mermaid. In the sphere of Miyazaki's other works, Princess Mononoke, Kiki's Delivery Service, Spirited Away, Howl's Moving Castle, etc., it pales in comparison.
(If you're new to Miyazaki, I recommend seeing either Howl's Moving Castle, or Spirited Away first.)