Sleeping Beauty, starring the third of the original Disney Princesses, and the last until 1989, is also the best. The animation is far more ambitious and experimental than what's found in their previous efforts, veering slightly from their house style, and incorporating a stylized, hard 2D rendering that subtlety evokes thoughts of the Bayeux Tapestry.
The decision to appropriate music from Tchaikovsky's ballet, rather than compose wholly new music, was also a brilliant choice that-perhaps ironically-adds a timelessness that the movie would have lacked had they chosen to go with contemporary music.
And, of course, there's Malificent-a truly amazing villain. Her plans for Prince Phillip are deliciously evil. At last, a villain who gets that there are fates worse than death!
Funny and romantic. Sweet and exciting. As far as I'm concerned, Sleeping Beauty is the absolute best of early Disney.