For USA, I think these are the top. http://vgchartz.com/swlaunch.php?reg1=America&game1=Grand+Theft+Auto%3A+San+Andreas+-+PS2®2=America&game2=Halo+2+-+XB®3=America&game3=Halo+3+-+X360&weeks=2
If you go back a couple of gen's some Nintendo games might have a shot, but we have no info about them, so for certain info: Halo 3 is tops.
If we're going a little on the wild side, Pokemon D/P had 1.4M first week, and I remember that being 3rd most. Pokemon Gold was most, and I think that had roughly 2.6M, and it might just grab second place, I'll check though.
Total USA list for lifetime: http://vgchartz.com/worldtotals.php?sort=america
Also, Welcome to Vgchartz!
http://www.vgchartz.com/games/userreviewdisp.php?id=261
That is VGChartz LONGEST review. And it's NOT Cute Kitten DS