Fantasia

I still find Fantasia one of the most beautiful pieces of animation in existence. Even if I never watched the Night on Bald Mountain sequence until I was in college and have always found the fish in the Arabian Dance sequence of the Nutcracker Suite oddly distressing (I was a weird kid).

And Fantasia 2000 is worth it for the Firebird section alone.

Both movies feature fantastic art and music, and come highly recommended. There are some parts in Fantasia however that have not aged well, in terms of social acceptance. Most of the objectionable content has been relegated to 'behind the scenes'.