I love Spirited Away and Mononoke, and Howl's is made by the same director - Hayao Miyazaki. They are quite moving emotionally and show some wonderful visual imagination, and they avoid the customary annoyingly cutesy features in animation films like those of Disney.
Spirited Away is a kind of Alice in Wonderland story, but with less of the insanity and more of an emotional thrust. Princess Mononoke is an epic adventure with environmental concerns done in a genereally non-preachy way.
Check these reviews of
Princess Mononoke and
Spirited Away. IMO they're quite accurate in their descriptions of these films
