I got a Gamecube on launch day. I really like it. I bought Rogue Leader which is awesome. I also really like Super Monkey Ball. My girlfriend and I play it a lot. It's great fun. The multi-player modes are good as well. I just wish the controller was a little bigger.
As far as the X-Box goes, I am pleasedd with it as well. I think Halo is one of the best games that I have ever had the honor of playing. There is something so rewarding about sticking a grenade on someone's face and watching them run around helpless. Everything about that game is superb. My only gripe about the X-Box is the controller. The buttons are too close together and are difficult to find and tell apart.