A few years ago I would have said Scottie Pippen, but with his recent financial issues it doesn't feel right to hit a man when he's down. I'd say at the moment Lebron James is the most punch-deserving.
I was going to say Tony Romo. But I figured this season has already been such a gigantic punch in the face for him, why bother.
Aside from the obvious to a Rockets fan (Malone, Stockton, Dirk), here is a guy that is just begging for it IMO: Get over yourself, Tom Brady. We know you're a great QB, but do you really need your own personal logo (hideous) and do you really have to wear that hat in every interview? You look like you've gone full r****d when you wear it. I also can't stand the way that you speak - like some Hollywood pretty boy that is better than everyone else.