For the first time in months, a new champion sits atop the Xbox Live User Activity List (which tracks games based on the number of users playing them in a given week.)

For a very long time, Halo 3 has ruled the roost, and few have been able to challenge it. However, a new post on Major Nelson’s blog has revealed the newest activity list, and Halo 3 has finally been dethroned.

The list for the week beginning December 22^nd:

1 - CoD: World at War
2 - Halo 3
3 - Gears of War 2
4 - Call of Duty 4
5 - Left 4 Dead
6 - GTA IV
7 - Guitar Hero World Tour
8 - Fallout 3
9 - Madden NFL 09
10 - Fable II

Gaining massive popularity on consoles with last year’s amazing Call of Duty 4: Modern Warfare, the latest installment in the series has taken the lead over Halo 3.