Ganondorf. Someone argued he's only good at manipulating people.. Even if that were true, manipulating someone in a game of chess is instant win. He's beyond intelligent. He's one of the few video game enemies that show real promise in their attempts at ruling the world.
Also, 'Sephie' would be too busy brushing his hair to pay attention to the impending checkmate in four moves.
Furthermore, because it has come up, should the board get thrown and they turn it into fisticuffs. .. Well Ganondorf again. I don't even need to say why 😛