Halo 3 sells 2.63 million copies in its first week as Xbox360 outsells Wii

[couchmonkey]

It's definitely possible that 360 was undertracked, it seems like big game releases like this are not VGChartz's strong point (just saying), but at the same time, it would have to be vastly undertracked for that number to not be disappointing.

Edit: still, nice work Halo.