I felt like listing the games that I own currently, so here we go:

1. Army of Two
2. Assassin's Creed
3. Assassin's Creed 2
4. Assassin's Creed Brotherhood
5. Battlefield: Bad Company 2
6. Bayonetta
7. Bioshock
8. Borderlands
9. Burnout Paradise
10. Call of Duty 4
11. Call of Duty: Modern Warfare 2
12. Call of Duty: Black Ops
13. Dead Space
14. Dead Space 2 (CE)
15. Demon's Souls
16. Devil May Cry 4
17. Enslaved: Odessey to the West
18. Fallout 3 (CE)
19. Fallout New Vegas (CE)
20. God of War Collection
21. God of War 3 (CE)
22. Grand Theft Auto 4
23. Gran Turismo 5 (CE)
24. Heavy Rain
25. Infamous
26. Killzone 2
27. Killzone 3
28. Little Big Planet 2
29. Lost Planet 2
30. Mass Effect 2
31. Medal of Honor
32. Metal Gear Solid 4: Guns of the Patriots
33. Need For Speed: Hot Pursuit
34. Ninja Gaiden Sigma
35. Ninja Gaiden Sigma 2 (CE)
36. Prince of Persia
37. Red Dead Redemption
38. Resident Evil 5
39. Resistance Fall of Man
40. Resistnace 2 (CE)
41. Sonic's Ultimate Genesis Collection
42. Tekken 6
43. Uncharted: Drakes Fortune
44. Uncharted 2: Among Theives
45. Unreal Tournament 3
46. Vanquish
47. X Men Origins: Wolverine
48. Warhawk

Am I missing any "Must Have" titles?