Three months and a week was all Halo 3 needed to become 2007's top selling game in the US market according to NPD, says Kotaku. It beat out Wii Play for the Nintendo console- you know, that title everybody bought to get the extra Wiimote.

There is a point where you have to begin thinking that some of Microsoft's comments about the health of the 360 "ecosystem" for third party developers have some merit. Wii Play came out with the console, so it was available for all of 2007, and it's the top seller on the platform. And here comes Halo 3 in the final quarter of 2007 and outsells it by nearly three quarters of a million.

It'll be interesting to see where Super Mario Galaxy sales end up. Mario is the flagship franchise for Nintendo, just as Halo has been for the Xbox. If the installed base for both machines is roughly equal (well, worldwide) but the top-selling Xbox titles consistently outperform the top-selling Wii titles, what does that say about which consoles are profitable for third parties?

Kotaku also has a roundup of Microsoft reaction to December NPD numbers.