well according to your recent post about invites to private trackers, it seems that you were flooding the boards with usless questions, but hey, its a question.
No Halo 3 is not worth selling your wii, if you have a 360 then buy halo 3, if you dont have a 360 then make that choice on your own, due to xbox having more mature games, while wii has more child oriented games. It is up to you, I enjoy both because I have both. Great investment on both parts.
i would say no. just w8 for a few months and great games are going to come out. here are some examples:
1.super smash bros, brawl
2.super mario galaxy
3.mario kart
4.mario and sonic at the olmpics
5.smackdown vs. raw 2008
6.soulcalibur(only in US)
7.the simpsons game
8.dragon ball(even if u dont like the cartoon, this game is worth to pick)