Novak Djokovic is currently one of my favourite tennis players, but I never knew that he was such a joker until I chanced upon this clip - the current world number 3 loves to fool around imitating other players. (There's a whole list of his other funny antics on YouTube right now.)
I think it's refreshing to see such a funny easy-going character on the sports scene where players are always so intense and serious. Novak shows that you can be world class and still be a funnyman. He's an versatile all-court player and has beaten Federer, Nadal and Roddick before, so a Grand Slam win might be possible next year if he can maintain his excellent form.
Watch out for this rising Serbian superstar.