Pom Poko. Another Studio Ghibli release (yeah, someday I'll see them all) and another one of my favourite movies of ALL FUCKING TIME. Seriously, after watching this stuff I'm convinced that Disney should have packed it in a long time ago and had these guys take over. So much more depth, complexity, emotion, imagination, etc. all without sacrificing the qualities that I imagine kids would appreciate.
edit: I'm about to watch another one, Grave of the Fireflies, a story about two young children orphaned by WWII in Japan. I'm at the point now where I'll shell out good money for any Studio Ghibli release completely blind. And theres a new one coming soon!