Princess Mononoke. I remember watching it for the first time, when I was getting into anime as a young teenager, and enjoying, but not quite getting, it. As the years have gone by, it is a film that has moved up in my estimations as I began to notice the subtler details of the story and characters. To the point where I came to the realization last summer that it is my favourite film. The story, characters, animation, music and direction are all stunning and subtlety realized. I always notice something new or a different way of looking at it when I watch it. Excellent dub cast/script as well, though I vouch for the Japanese version.