COD 1, UO, 2, 3, 4 and 5 never ticked me off. In fact, it was incredibly rare that a game actually got under my skin. COD 6 just managed to be the most aggravating game ever manufactured. Everything about it pisses me off: the multiplayer, the matchmaking, team-making, weapon unbalance, community, lack of features, map design, knife runners, luck, thermal, Models (their underpoweredness) - which could relate to the strange relation between weapon efficiency and level of unlock, i.e a weapon unlocked at a higher level will be weaker than a weapon from level 1.
Do you see my point? Call of Duty does not annoy me, but Modern Warfare 2 has to be the most frustrating game I've ever played.