Who do you think would make a good libertarian or libertarian leaning candidate for 2012?

I'm not asking for libertarian purity or a member of the Libertarian Party necessarily, more so a balance of a good amount of libertarian principles and viability. Some names come to mind are Rudy Giuliani, Sarah Palin, Mark Sanford, Gary Johnson etc. Who do you think would be a good libertarian or libertarian leaning candidate?