I really like Hunk! He's a big teddybear, and even if he looks like the "stupid fat guy who eats all the time" type, he's actually pretty smart (after all, he WAS an engineer back at the garrison), and cares a lot about others! I think he'd be a great person to have around and be friends with!
My favorite would be Keith. <3 I know he's Not-headed and such, but he just has a unique view on things, that's been twisted just a bit from how he grew up. And he has a mullet. He pulls it off pretty well, you have to admit.