McCain. I'm no fan of his, but I'll take the lesser of two evils. As a conservative, we didn't exactly have any good choices this time around.
Obama is charming, and displays leadership ability in scripted situations, but he fumbles horribly in impromptu situations. Heck, he makes Bush look like a genius in those instances. That _is_ the primary thing that I hear, that he's charismatic, and a great leader. But you have to ask yourself, would he lead us in the right direction? I would argue not. I don't think I've heard a good idea out of him yet.
I'd take Reagan back in a heartbeat. Heck, I think Reagan could govern better from beyond the grave than these two.