Mashiro, do you have the component cables for the Wii? I've heard that they really show off how jaggy the Wii's graphics can be (except Medal of Honor Heroes 2 which features full screen anti-aliasing). Wii Fit is pretty jaggy, but Lost Wind is very smooth looking.
Mashiro, I hope to one day have a go on Halo 3 with you. I have yet to do an online co-op game, though I have done multi-player to death.