Jay Carney.
IMO Sean Spicer was worse. I guess it's not an easy job and not everyone is cut out for it.
My favorite press secretary story is Robert Gibbs, who ended up at McDonald's after leaving the administration. You could say he ended up as the modern equivalent of Ronald McDonald, and they call Sanders a clown?!
The press secretary is a puppet. The problem with being a (figurative) puppet is that it's almost impossible to speak up on your own. Any flaws of your employer end up being reflected on you, and you can't defend yourself.