Reagan was even better than Clinton in a press conference, although that could be open for debate. Are we judging delivery or content?
George W. Bush was the worst in modern times and rarely appeared, giving awkward and scripted and even clumsy presentations.
President Obama is a a league of his own, laughing, non-defensive and entertaining, even educational. It is something rarely seen in modern politics and it is fascinating. Here is an example of a man on the spot: