Loki is a villain with intelligence, motive, and a fatal tendency to out-think himself, which is something I'm intimately familiar with. Plus hey, he guilt-tripped himself into not!suicide. That boy has issues and is in clear need of cuddles. (I also loved his scene with Frigga, where it's clear that he adores her beyond measure.)

Mind you, he's matched in Thor being mostly mature, rather than the "aren't I cool??" antihero Stark, or somewhat hyperactive and moodswingy Spiderman. And I really liked the way the girls were handled - Sif being the more-or-less leader of the Warrior Three, Frigga laying into the Frost Giants with his sword, and the Jane-Darcy mentor-mentee relationship. I think I can stand behind this take on superhero movies. Here's hoping X-men:First Class is of the same class!