DonWii on 17 January 2008
Rock Band, across all platforms, is over 1M.
"Despite only two months at retail, and having an average retail price of over $160, it brought in sales (across platforms) of over $180 million."
http://www.gamedaily.com/articles/news/npd-us-video-game-industry-totals-1794-billion-halo-3-tops-all/19119/?biz=1&page=2
