When You Wish Upon A Star: Nothing more needs to be said that others here already haven't. Disney anthem. A true classic.
Let it Go: This is still "the song" of modern Disney animated movies and belongs up here, even if not my personal favorite.
Circle of Life: If one were forced to pick an anthem for the Renaissance Period...I think this would have to be it, right? It's a loaded period of Disney's best music. But this one has got to be the most iconic from that period, even if not the best.
A Whole New World: I am picking this as my last selection because this song was the winner of the last two Disney music tournaments hosted on this board. So that's got to count for something.