It currently has 11

1. Call of Duty: Black Ops
2. Call of Duty: Modern Warfare 2
3. Halo 3
4. Kinect Adventures
5. Grand Theft Auto 4
6. Call of Duty: Modern Warfare
7. Halo: Reach
8. Call of Duty: World at War
9. Gears of War 2
10. Gears of War
11. Halo 3: ODST

Games out already
12. Assassins Creed (4.99)
13. Forza 3 (4.90)
14. Assassins Creed 2 (4.62)
15. Red Dead Redemption (4.39)

Upcoming games
16. Gears of War 3 (shoe in)
17. Modern Warfare 3 (shoe in)
18. Halo: CE Anniversary (80%)
19. Grand Theft Auto V (shoe in)
20. COD 2012 (shoe in)
21. Halo 4 (shoe in)
22. COD 2013 (shoe in)

Possibles
23. Forza 4 (bundled heavily?)
24. COD 2014 (still selling well on 360 when next gen is in full flow?)
25. Assassins Creed 3 (end of a trilogy)

Think it can do more than 25??

i think it can do it.

I vote 25. Don't think Assassins Creed 3 will make it, but I do think there will be at least one more title similar to red dead redemption in that it is not a well established franchise, but manages to sell a lot due to the amount of critical acclaim it receives.
Battlefield 3 also seems to have a small chance if EA ramps up its advertising campaign to focus specifically on the aspects of cod that even cod fans hate.

Voted for 20 a safe number that's doable even if a new MS console comes out in early 2013. Also think that Forza 4 should be a shoe in for selling over 5 million copies the game looks fantastic. Sure it could be bundled heavily to reach that number but doesn't have too Forza 3 sold over 800k more units then Forza 2 even though it was bundled a lot less. Forza 4 should easily sell 500k more then Forza 3.

This is an interesting poll. I think 25 is a good goal.

The first 11, already in. Assassin's Creed 1, 2, and Brotherhood are all also likely (Brotherhood is outselling AC2 i believe for the time). That's 14. Add CoD MW3, and 2012, that's 16. Then Gears 3 and Forza 4 are basically garenteed, that's 18. Both upcoming Halo's should break 5 million as well, that's 20. Then I feel at least 1 more Kinect game (maybe Kinect Sports) will break 5 million, that makes 21. Red Dead Redemption makes 22, and well hm.. Get's tought here. Battlefield is growing, and I honestly feel Battlefield 3 will break 5 million on 360. Bad Company is a joke, and BC2 is breaking 3 million now. So I'm at 23 now. After that, who knows...CoD 2013 will likely break 5 million, but I'm not sure about Assassin's Creed 3. The rest barely inched past 5 million, and the finale will come very late in the generation. Either way that's 24 games for me, plus 1 extra for some unannounced title.

25 looks good, but it's no garentee.

I think your missing Assassins Creed Revelations.

Edit: Nevermind.

I think it will just miss 25 and end up with 24. ( I actually think Assassins Creed 3 will be out for the 720 / PS4 )

Nonono.

Yeah I definitely think its possible.

Read the title.

Hmmm.  Well how many does it currently have?

Read the beginning of the OP.

11?  Well forget that.  No way now h---

Read the rest of the OP.

Wow.  Color me shocked.  Not only does it look possible, it looks likely.  And, to be honest, who knows how games like Kinect Sports or Dance Central will sell again come holiday (remember how popular Wii old titles always spiked back up?).  Good research, Seece.