Grand Theft Auto IV (Xbox 360)
Variety: GTAIV Launch Bigger Than Halo 3 (And Then Some)
Kotaku - April 15, 2008
Submitted by lstormy10 (27) at 7:05PM PST on April 15, 2008
"Variety are reporting that, according to 'sources close to publisher Take-Two,' Grand Theft Auto IV is poised to take in around $400 million during its first week on sale. They're also reporting that, based on discussions with retailers, the 360 version is easily outselling the PS3 one."
Make sure you account for sales of limited edition versions (I don't know if you already have in your number).