That's such a hard question (and I don't know which ones are still out, and Cinderella is not out yet)!
But answering for *me* and not for my kids, it'll depend on what I'm looking for and what my mood is:
- beautiful animation and music, serious non-kiddy themes: Hunchback (nobody else ever likes this one)
- classic fairytale: Cinderella
- heroine who isn't "weak": Beauty and the Beast and Mulan
- romance for kids: Lady and the Tramp
- really funny satire: Lilo and Stitch
- trying to permanently damage and psychologically scar toddler, ensuring a fear of all things Disney, for all time to come: The Black Cauldron