I really love Aladdin (especially when they sang 'A Whole New World' lol), The Incredibles, and Big Hero 6. I can watch these three as many times as possible and I would never get tired of them.
I love almost all of Disney's current animation movies they seem to be on a roll (I especially loved Wreck-it-Ralph and The Princess and the Frog). Of older ones it's a bit harder to choose. Top favorites though would probably be Mulan and Beauty and the Beast (Aladdin and The Little Mermaid are pretty close seconds). Favorite Pixar will always be Toy Story 2. Oh and also Lilo and Stitch and Brother Bear (I really think this one is crazy underrated).