I've only met Thor, like, once, but I'd have to say Steve. Unless the Steve in your world is way different from every other Steve out there.

[Which is definitely a possibility.]

And I think he'd probably be kinda hurt if we picked Thor over him, and Steve has this whole kicked puppy look going on when he's disappointed. Well. Mine does, I don't know so much about the other one. Or yours, if he's kicking around somewhere.