Gerald McBoing-Boing, 1950
This UPA animation done by John Hubley is one of the greatest examples of how important sound design is to an animation. Matter fact, this very piece is all about a boy, Gerald, who cannot speak except for his abilities to make great sound designs as a way of expressing himself.
I am running a summer camp of sort to entertain my daughter and her friends for two hours a day so they have something to look forward to that's engaging and I showed at least one great animation everyday. I was pleasantly surprised that this is overall favorite of theirs. It just shows you great animation with a good story and execution never go out of style.