Director: Miyazaki Hayao, 2008
Pros: lighthearted story, excellent animation, great kids movie
Cons: artwork isn't as polished as other Ghibli films
Ponyo (or Ponyo on the Cliff) is a Japanese retelling of the Little Mermaid, with several twists. There's a stronger ecological undercurrent than Anderson's fairy tale had, and the protagonists are children, rather than adults ready to make life decisions.
When five year old Sosuke rescues a fish and names it Ponyo he had no idea the trouble it would cause. Ponyo's father quickly recaptures her, bringing her to his undersea home. She escapes and uses her magic to become human in order to rejoin Sosuke. But her actions cause major flooding and threaten to destroy the world.
The story is cute, reminding me of My Neighbour Totoro. Some parts are confusing as there is little explanation but the majority of the plot is simplistic. It's more a visual film, which is too bad because while the artwork is good, some characters (Ponyo's father being the first that comes to mind) look less than polished for a Studio Ghibli film.
It's not my favourite Miyazaki film, but it is worth seeing, especially if there are kids to watch it with.
Disney's youtube page has disabled the embed function for movie trailers for some reason, so if you want to see the trailer for Ponyo, click the link.