WiiSports will come first, but that's not a very fair comparison given its bundling.
I do think WiiFit will be the top non-bundled game this generation - and it has a real chance of selling 10m units this year alone. Its still doing approx 100k / week in Japan - 2 months after release.
Gesta Non Verba
Nocturnal is helping companies get cheaper game ratings in Australia:
Wii code: 2263 4706 2910 1099