Call of Duty: World at War or Disgaea 3? (PS3)?

At the moment I need a new game, and I don't have nearly enough to get Red Dead, so I'm stuck between choosing whatever I can find. My top choices are CODWAW and Disgaea 3, but I might get something else. What I am asking is, what would be recommended.



My favorite game types are: Shooter and Sandbox (GTA, SR), although I like some other games like MGS4.



Games:

Metal Gear Solid 4

Fallout 3

Assassin's Creed 2

Saint's Row 2

InFamous

Call of Duty 4: Modern Warfare

Call of Duty: Modern Warfare 2

Bioshock 2

Resident Evil 5: Gold Edition



So, you guys have any recommendations?



Also, I owned and liked the previous 2 Disgaea games, but I never beat them without cheats (I have the shooter fan sort of patience, at least with games).Call of Duty: World at War or Disgaea 3? (PS3)?
I'll take Call Of Duty: World At War.