Candidate Obama gave great, inspiring speeches, but wasn't that good at real-time conversation. (President Obama not so much.) Dubya Bush always looked like a deer in the headlights, amazed that he was getting away with what he said and hoping nobody would ask questions about it.
But the guy who was really good? Bill Clinton. He was always on, always quick thinking, always had a good comeback for anything, lots of fun to listen to. Sure, he was lying through his teeth half the time, but he knew which half it was, and he did it with a smile that said that he knew that you knew he was lying, and that he'd make the game worth playing, and he usually did.