Gary Johnson, of course. But he isn't going to.
The more interesting question is which of the two major party candidates I want to win. What I find interesting, looking at my own feelings, is that there are two different answers.
.. when Romney talks a free market line but fails to act it, those of us who actually believe in free markets will get blamed for the resulting failures. That, after all, is what happened with the Bush administration. I do not expect either Obama's policies or Romney's to succeed, and if policies are going to visibly fail, I would prefer that they be blamed on someone else. That is an argument in favor of Obama.
My conclusion is that I have little reason to want Romney to win, some reason to want him to lose. I am not confident of that conclusion ..
If I switch the question from what I ought to want to what I do want, from reason to emotion, the result changes. I will be happy if Obama loses, unhappy if he wins.