I would vote for Obama because Mitt Romney's "values" kind of suck. I don't mean to sound like a friend here, but I think Ron Paul would be better than Obama or Romney, too bad no one votes for him "because he can't win."
Ron Paul really couldn't win unless he would have gotten the Republican nomination. The United State's two-party system is forgeted up so much third parties don't have a chance. If he did run as a third party, he gain enough traction to split the Republican voters, but that would just result in Obama in winning.
The actual Libertarian candidate is
Gary Johnson, he actully seems like a pretty cool guy and doesn't afraid of anything, but sadly he probably doesn't have a chance.