Wow, this is a tougher question than I thought at first! I like The Little Mermaid, even though the rebellious aspects of Ariel's behaviour are a bit cringworthy for a parent of a teenager. Aladdin would be a good choice. It has a fairly good plot, a suitably nasty villain, and of course, Robin Williams was just unbelievable as the Genie. But...My favourite movie from Disney is The Lion King. It has it all, the best songs, a strong plot, memorable and vivid characters, and a very slimy, yet satisfying, bad guy. Hamlet, except with claws, and the prince lives!