In no particular order
Iria
Bleach
Final Fantasy: Advent's Children
Buso Renkin (only saw a few episodes, but it looked good)
Princess Mononoki
Spirited Away
Howl's Moving Castle
Ghost in the Shell (more the second movie than the original)
Bagi, the Monster of Mighty Nature
Does the live-action version of "Speed Racer" count?
Does Samurai Jack count? (I have cosplayed as him).

I'll get around to watching Princess Tutu and/or Code Geas one of these days.