I agree that XBOX can't and probably won't be as good as GC. At least for me since I like Shiggy's games like Mario, Zelda, etc. And, I don't care for the violent and FPS games on xbox (and psII). The other console makers just don't have games with a following like Nintendo's classic characters. Sega tried, but now Sonic is on the GC.
The thing that helps sells of xbox and ps2 is that they can play dvds. Xbox is even rumored to be working on a version that will record live tv, mp3s, etc. on its hard drive and maybe even have a mouse and keyboard. That would increase their sells to people who are looking for more entertainment features than just playing games. For me though, it seems that Nintendo will be the best as far as the games are concerned.
Some people have said that Nintendo consoles have been going down hill. The N64 wasn't as good as the SNES? Of course, the N64 was a better system then the SNES, it's just that the SNES had a lot of, and some of the best games ever. Third party game designers started moving to PS since it was much cheaper to make thier disks then the N64 carts. Now that the GC has disks, they have been making a lot more games for Nintendo allbeit in some cases crappy games like were on the PS1. Eventually, I think that more of the big game makers like Squaresoft, Rare, Capcom, ..., and Nintendo will make a lot more QUALITY games for the GC.