11. Donkey Kong
Game: Mario Tennis Series
Mario was Nintendo's well rounded golden boy (and by far the most athletic plumber the world's ever known). But Donkey Kong would just play the net and smash over and over in a relentless assault of simian rage. In theory you could pop a lob shot over his head except that the lovable gorilla had the wingspan of four Roger Federer's and besides you had so little time to return his volleys that implementing a strategy was completely out of the question.