27 Romney lies from the first presidential debate
Strictly speaking, I would say that some of those 27 items are misleading formulations, prevarications, distortions, dubious claims, groundless assertions, and/or mythical right-wing slogans rather than straightforward lies. But most of them are lies, and all of them are (more or less) dishonest. You can review them and come to your own conclusions.
As the video notes, this is only a partial compilation. And it's hard to know precisely how one would score some of Romney's other whoppers. For example, in response to the contention that his proposed tax cuts would increase the deficit (a conclusion that can be described as "almost certainly correct" rather than "obviously correct" only because Romney, implausibly, claims that he will magically offset the tax cuts by closing loopholes ... which he doggedly refuses to specify), Romney said this:
My No. 1 principle is there will be no tax cut that adds to the deficit. I want to underline that: No tax cut that adds to the deficit. [....] So there's no economist that can say Mitt Romney's tax plan adds $5 trillion if I say I will not add to the deficit with my plan.(That should sound familiar. In 2000, George W. Bush also indignantly denied that his proposed tax cuts would increase the deficit. How could that mean Al Gore, with his "fuzzy math," ever suggest such a thing?) Should that be described as a lie, a fairy tale, a ridiculous tautology, a manifest absurdity, or some combination thereof?
Still, this video offers a useful preliminary catalog of Romney's mendacity from that one debate performance.