Microsoft’s Major Nelson has revealed the top 20 games played on Xbox Live for the week of March 5. The activity is measured by uniques users, not hours played. As long as the console is hooked to the net, whatever you’re playing (single-player or multiplayer) counts.

Here’s the list:

1. Call of Duty: Modern Warfare 3
2. Call of Duty: Black Ops
3. FIFA 12
4. Battlefield 3
5. Halo: Reach
6. Modern Warfare 2
7. Mass Effect 3
8. Skyrim
9. NBA 2K12
10. Gears of War 3
11. GTA IV
12. Forza Motorsport 4
13. Madden NFL 12
14. NHL12
15. FIFA Street Demo
16. Saints Row: The Third
17. Halo 3
18. Mass Effect 2
19. NBA 2K11
20. Call of Duty 4

Special Note: We’ll be running these 360 activity charts for a few weeks as a test run, please let us know if you enjoy it. Unfortunately, there is no official activity numbers for PSN and PC (impossible to track due to multiple services and independent ones).