Grand Theft Auto IV began shipping early last week, and it's already making waves across the Xbox 360 and PlayStation 3. Microsoft and Sony Computer Entertainment were quick to tout the immediate benefits GTA IV's release brought to their respective platforms.

Xbox 360 and Xbox Live director of product management Aaron Greenberg already expected GTA IV to drive new XBL memberships, predicting Rockstar and Take-Two's title to become the most played XBL title in due time.  In fact, last week GTA IV managed to do just that, with the highest number of unique users seeing multiplayer action. Losing its title as Xbox Live champion is Call of Duty 4, while Halo 3 continues to follow close behind Activision's tactical shooter.

The Xbox 360 version of GTA IV is set to bolstered with unique, downloadable episodic content which stands to not only cement its popularity at retail, but over XBL as well.  GTA IV will be sticking around on the XBL charts for a while.

Xbox 360 Top Live Titles (2008/4/28 - 2008/5/5)

1. GTA IV
2. Call of Duty 4
3. Halo 3
4. Guitar Hero III
5. Gears of War
6. Rock Band
7. Tom Clancy's Rainbow Six Vegas 2
8. Iron Man Demo
9. FIFA 08
10. Forza Motorsport 2