If you asked me who was the most appalling evader/distracter/dissembler among White House spokespeople over the time I've been politically aware, I'd have to say Ari Fleischer, who served in that position for the first couple of years of George W. Bush's administration. I remember often shouting at Fleischer on the TV as he spun some inverted version of the truth to the press, inventing absurd new terms (Remember "homicide bombing"? Don't ask.), telling Americans to "watch what they say," and most of all, just shamelessly denying what everyone knew to be true (Jonathan Chait penned the definitive takedown of Fleischer). On the other end of the spectrum I'd have to put Mike McCurry, who did the job under Bill Clinton, including the period covering the impeachment scandal. McCurry wasn't any more forthcoming than anybody else who has held that job, but he had an easy, straightforward manner that seemed to make the interaction between himself and the reporters more of an honest negotiation over what information they could get, and less some kind of game whereby the spokesperson tries to deceive and the reporters try to catch him/her at it.
When current White House spokesperson Jay Carney took the job, he seemed like the perfect person for it. An experienced reporter himself, Carney knew the press corps as a former colleague, and in his frequent television appearances while at Time magazine he came off as articulate, informed, and thoughtful. But Carney has been less than a smashing success. He doesn't have the blatant contempt for reporters that Fleischer had, and the times he's been caught saying something untrue have actually been relatively few in number. The problem isn't so much what he says, but rather that he refuses to say much of anything. In fact, he's got a dozen different ways to say that he won't answer your question. Or actually, as it turns out, a baker's dozen. Yahoo News did the yeoman's work of analyzing all of Carney's briefings, and here's what they came up with: