COD4 because of its purity, best balance of gameplay and skill, based more on kills and not killstreaks. Has some of the best glitches in all COD games.
World at War maps huge as fu o.o too bad it got hack it would be nice if 3arc recreates the game on HD but with the same weapons and story line and of course no hackers e.e
World at war was the shit for real...
-First Zombies
Good online map and guns
That was sick its was the only game whit tank and look like a Real War
LoL I still remember the glitch to go under the map in the chineese castle (I dont remember the name of the map but that was funny how 2-3 person each team were trying to go under the map)