This is a pretty pointless post, but I'm just putting myself on the record early. John McCain is my favourite but he has little chance (though I'm not really sure why). Barrack Obama comes next and he has a better chance. Hilary Clinton and Mitt Romney are the most likely to win I think.
Each of the candidates offer intriguing novelties; Romney's a Mormon, Clinton's a girl, Obama's black (kinda), Giuliani's crazy etc. So it'll be fun to watch the whole thing go down.
My least favourite candidates are Romney, Huckabee and Edwards, so it'll probably end up being one of them.