Disney Animated Canon/Awesome

Snow White and The Seven Dwarfs

When the Queen transforms herself into the hideous peddler. It was a huge challenge for the animators to not only depict her changing, but to show how she felt as she Did. The result has served as Nightmare Fuel for generations, but it's also a truly awesome One-Winged Angel moment, and it shows just how evil she is - as suggested by Hans Conreid's Magic Mirror in the Disneyland TV show's "Our Unsung Villains" episode, she may be a Vain Sorceress, but her hatred for Snow is enough to trump even her vanity for a time ("just so you wouldn't get bored with this story," the theme of the special was how villains are underappreciated for the conflict they provide that makes good drama). (Runner-up: her gleefully watching Snow succumb to the poisoned apple.)
The whole movie qualifies, at the time it was made a feature-length animated film was nothing short of miraculous. The fact that Walt and Co. made such a stunning and enjoyable one was an outcome no one planned on.
The dwarfs chasing the witch through the forest and up the mountain. And Grumpy's the one leading the charge!

A meta-example. On Disney's planned lineup for upcoming animated movies, Mickey Mouse, the company's biggest star and mascot, is getting a movie of his own. Not a Direct-To-DVD movie, but a full-fledged theatrical film. Given how Mickey's career has been made up of appearing in cartoon shorts, television specials, video games, merchandise, but never a full-length theatrical movie centering around him, it really shows how far Mickey has gotten.