As far as crossovers go I think I'm most familiar with the Final Fantasy characters being in mario hoops 3 on 3 for the DS (ninja, white mage, and black mage). It was interesting the first time you see them in the rainbow cup because you at first think that you beat all the cups and have everything going good then ninja just comes down and swipes the trophy to his ship and then you gotta play his crossover crew on the ship to win the trophy back. Plus their special shots are amazing.