Best superhero system?

[Macrovore]

Hey, guys
I was wondering what was the best superhero system, and for what reason? I just picked up the Mutants and Masterminds book, and it looked really cool. Kind of a superhero d20 system. But there's also the Hero system, and the newer Icons. What's different between all of these superhero systems (and perhaps others)?

[Starscream]

Mutants and Masterminds is my favorite by far. Game balance goes out the window if the GM isn't careful, but let's face it; comic books are like that too. Does anyone really think Aquaman should be on the same super-team as Superman?

But yeah, the system captures the feel of comic books far better than any I've ever played. I also find that it's a great system for non-superhero modern age campaigns. So many action movie characters could basically be described as low-level supers with extra endurance and just slightly super-human abilities.

[Swordgleam]

I've been hearing good things about Icons. I think it's supposed to be fairly rules-light, as opposed to the crunchier d20.

I'd probably go with Wushu if I wanted to play/run a supers game, but it isn't designed for supers, just for zany hijinks of that sort.