I think it's fair game to include any that won Best Picture or were nominated for Best Picture (so add Chicago, Gigi, An American in Paris, Moulin Rouge, etc.)
There is the perfection of THE SOUND OF MUSIC, WEST SIDE STORY, THE MUSIC MAN and MARY POPPINS. Everything else is inferior. No matter what AFI or some other trumped-up pannel of "expertts" says. Doesn't mean there aren't some entertaining films among the others.