Haha, I LOVED his Hammer. Whenever people say that Iron Man 2 has a "weak" villain I'm always like, "What? Sam put so much into that role!"
And then I realize they mean Whiplash.
Despite the fact that Whiplash is the first and last fight, I always kind of consider Hammer to be the big bad in that movie. I mean, in fairness, if it weren't for him Whiplash would have sat around in jail after his initial attack. Hammer gets him out and gets him the supplies to make the later finale happen. Plus Hammer has a more solid motivation, and I love his interesting relationship with Tony. And, yeah, Sam was just great in the part.