In a blog post from Microsoft's Major Nelson, the company revealed that Call of Duty 4: Modern Warfare was the most popular game on the Xbox Live service for the week ended January 14.
This marked the first time that a game has surpassed the online popularity of Halo 3, which remained in the number one spot since its launch in September 2007. Halo 3 remains popular, however - it merely dropped to the second spot.
Based upon unique users, the most popular Xbox 360 Live titles for the week ended January 14 were:
1. Call of Duty 4: Modern Warfare
2. Halo 3
3. Guitar Hero III: Legends of Rock
4. Gears of War
5. Rock Band
6. Madden NFL 08
7. Assassin's Creed
8. Mass Effect
9. FIFA 08
10. Forza Motorsport 2