Madden sucks on the 360.
I bought it just because I buy every game system. But, there hasn't been much greatness on it, yet. The only game I really play is NBA 2K6. The graphics are good in this game, but they aren't THAT much better than the PS2 version.
Madden though, you can tell they rushed this years out. They just built a new engine and shit, and didn't really make sure everything works right. I was playing a friend, and I was down like 28 pts, so I just started throwing hail mary's on every down, and they were working.. even when I was like on the four yard line. and it kinda bugs me that it doesn't have the passing cones.
I would pass on 360 for now. It'll probably get cheaper when PS3 comes out, and there really isn't anything worth getting on it. Until Saint's Row comes out. That game looks sick. But, that probably won't be out for another few months. The best thing about it is downloading demos.