I like KZ2 campaign more than the multiplayer. And KZ2 and MW2 both bored me despite me liking Cod4.
The maps in MW2 are shit, so much damn cover everywhere, the weapons are so strong, the killstreaks are a mess. The copper gunner for example is a bad killstreak. Once someone gets it, it's game over for the other team. The campaign in MW2, while having fun spots in it was just all over the place, the story was stupid unlike Cod4's great campaign.
Not to mention the maps in Cod4 are vary varied and very balanced. There cover here and there but there's open space to pick out enemies. Cod4 was a very balanced game.
Another thing is that the submachine guns in MW2 are useless compared to the Assualt rifles, again in Cod4 it was balanced.
So: Cod4 > KZ2 > MW2.
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