I'm going with Mitt, but only slightly and mostly based on presentation.
He wiped the floor with Obama. Looked at him directly when he spoke, used specifics and figures, used anecdotes, addressed Obama's points head on.
Obama looked lost.
The highlight of the night:
Romney telling Obama that if he wants to hire teachers so badly, he used $90 billion to help fund green energy companies, half of those companies are out of business and the people running those companies were Obama donors. Wouldn't those $90 billion have been better used to hire teachers?
Obama didn't even bother addressing it.