Also have to go with Aladdin here. That was, like, THE Disney movie of my childhood.
Edit: It's also important to note that Williams (and Gilbert Godfrey) being in that movie were, along with what the Simpsons were doing in TV at the time, what helped make voice acting into something that stars did, which was hugely important to American animation that followed (even only a few years later, like Toy Story starring Tim Allen and Tom Hanks, or 10 years after Aladdin, Shrek with Michael Myers, Eddie Murphy, and Cameron Diaz). Stars didn't work in animation, prior to this, unless they were very washed-up (for instance, one of Orson Welles' very last performances was as Unicron in the Transformers movie in the 80s)