It was very hard to choose my top Miyazaki film, but I choose Nausicaä of the Valley of the Winds. At first, I had never seen the film, until I had bought the Disney 2-Disc DVD of the film. I thought the dub-casting was excellent, with Alison Lohman as Nausicaa; Shia LaBeouf as Asbel; Patrick Stewart as Lord Yupa, and Uma Thurman as Kushana.
The film is based on a manga made by Miyazaki himself. Set in the year 2984, a thousand years in the future, when global war had incinerate the Earth. The Earth has become an unrecognizable place. Large parts of the world have been swallowed up by forests of poisonous fungi. The remaining humans live near the fungus and it's monstrous insectoid inhabitants, trying to prevent it's spread. One of the human kingdoms, the peaceful Valley of Wind, loves its gentle Princess Nausicaä and her father the king, but their peace is about to be broken, as they are swallowed up in the machinations of their larger, warmongering neighbours. However, Nausicaä has hidden potential, and may yet change the fate of the world.
It's truly Miyazaki's epic masterpiece, and also a good film to show us the seriousness of global war and our environment.