CoD2 had my favorite campaign for it's total Nazi slaughtering in well designed levels and fun sidekicks in the British campaign, multiplayer was a little underwhelming though. CoD4 had some intense story-telling as it managed to make me feel like a badass superhero on moment and then feebly fleeing from (or being dragged to) my demise, but was short and extremely cheap on Veteran difficulty. The multiplayer was really great and ate up a great deal of my time, but is pretty much eclipsed by MW2's. MW2's campaign was excellent at parts (The U.S. and Rio levels were truly sublime) but the story itself was extremely rote and predictable (even by CoD standards) and way too short.