The Wizard of Oz. Great opportunities for divertissements for the scarecrow, lion, tin man, good witch, and evil witch. Also, children's parts because of the munchkins...Maybe music could be an extended orchestration of the movie score.
I've also always wanted to choreography a Mario ballet. He would pass through all sorts of trials, only to realize that "the princess is in another castle," so ends act one. The backdrop would be slowly moving from right to left, just as it did in the old games. Again, music would HAVE to be an extended orchestration of the game's score.