Including the most infamous liar among all modern Presidents, Billy The Rapist. At least The Rapist had the decency to word his lies cleverly and elaborately so that, with sufficient "parsing," you could break the code. Obama just doesn't care. No parsing, no lip biting antics to induce superficial plausibility. He figures we're too stupid to be worth the trouble.
I think Harry Reid, however, may top even Obama as a jaw-droppingly brazen liar. Remember him asserting emphatically, during the phony Whitehouse health care summit, that no Senate democrats were talking about using reconciliation to pass the bill? I don't recall the camera showing it, but even Obama had to be giving him a "WTF?!" look over that one.