The OP got me wondering... What are the biggest 1st week sellers this generation? Let's find out. 
360:
1. Halo 3 (3,815,444)
2. Grand Theft Auto 4 (3,377,873)
3. Gears of War 2 (1,896,244)
4. Call of Duty: World at War (1,301,675)
5. Fable 2 (1,049,788)
PS3:
1. Grand Theft Auto 4 (2,547,973)
2. Metal Gear Solid 4 (1,711,226)
3. Call of Duty: World at War (735,630)
4. Gran Turismo 5 Prologue (639,548)
5. Pro Evolution Soccer 2009 (613,801)
Wii:
1. Super Smash Bros. Brawl (2,767,256)
2. Mario Kart Wii (2,408,699)
3. Wii Fit (1,626,973)
4. Super Mario Galaxy (1,075,164)
5. The Legend of Zelda: Twilight Princess (820,122)
DS:
1. Pokemon Diamond/Pearl (3,501,701)
2. New Super Mario Bros. (1,218,484)
3. Pokemon Mystery Dungeon: Explorers of Time/Darkness (1,067,874)
4. Pokemon Platinum (992,995)*
5. The Legend of Zelda: Phantom Hourglass (707,542)
PSP:
1. Monster Hunter Portable 2nd G (857,429)*
2. Monster Hunter Freedom 2 (807,298)
3. Crisis Core: Final Fantasy VII (778,735)
4. Dissida: Final Fantasy (503,401)*
5. God of War: Chains of Olympus (237,474)
All Together:
1. Halo 3 (3,815,444)
2. Pokemon Diamond/Pearl (3,501,701)
3. Grand Theft Auto 4 (3,377,873)
4. Super Smash Bros. Brawl (2,767,256)
5. Grand Theft Auto 4 (2,547,973)
6. Mario Kart Wii (2,408,699)
7. Gears of War 2 (1,896,244)
8. Metal Gear Solid 4 (1,711,226)
9. Wii Fit (1,626,973)
10. Call of Duty: World at War (1,301,675)
11. New Super Mario Bros. (1,218,484)
12. Super Mario Galaxy (1,075,164)
13. Pokemon Mystery Dungeon: Explorers of Time/Darkness (1,067,874)
14. Fable 2 (1,049,788)
15. Pokemon Platinum (992,995)
16. Monster Hunter Portable 2nd G (857,429)
17. The Legend of Zelda: Twilight Princess (820,122)
18. Monster Hunter Freedom 2 (807,298)
19. Crisis Core: Final Fantasy VII (778,735)
20. Call of Duty: World at War (735,630)
21. The Legend of Zelda: Phantom Hourglass (707,542)
22. Gran Turismo 5 Prologue (639,548)
22. Pro Evolution Soccer 2009 (613,801)
24. Dissida: Final Fantasy (503,401)
25. God of War: Chains of Olympus (237,474)
*Japan only
If you see anything that needs changing, give me a holler.
