Oh Loki for sure. Yes, he's a morally ambiguous dickhead, was the primary cause of just about every problem the other gods ever encountered (to the point where they'd just automatically blame him even if he had nothing to do with what was happening), basically sets the end of the world into motion, and technically he's a giant and not actually numbered among the aesir.
BUT he's also completely unrepentant about anything he's ever done, just as frequently bailed the other gods out of situations as he got them into them (even when he hadn't actually DONE anything), and he frequently outsmarted everyone. I can't help but admire a god that stands by what he's done, both good and bad, regardless of the consequences. Not only does that take some serious balls, but some major dedication too.
So yeah, Loki FTW.