I love so many of them, but I had to vote for Beauty and the Beast. I saw it in my early 20s when it came out, and I sobbed the whole way home. I was so glad it was the first animated movie ever to be nominated for a "Best Picture" oscar. SO GREAT!
There are too many to name all the ones I love so much, but off the top of my head,
Cinderella
Sleeping Beauty
Mulan
The Little Mermaid
Lady and the Tramp
101 Dalmations
LOVE THEM ALL!