Mitt Romney went into the governorship of a highly Democratic state, and balanced the budget there without raising taxes. Right now, I'd vote for him over any of the other candidates simply based on that.
Last time, I voted Libertarian, knowing that that party's candidate couldn't possibly win. It was kind of like voting for "none of the above", while at the same time saying that we need to cut back the size and power of the federal government. I may be forced to do the same again, depending on who gets the nomination.
If enough voters would join me, we might make some real changes to the federal government.