MW1: A really great single player campaign, with great mutlplayer to boot
MW2: Single player wasn't bad but comparing it to MW1 shows its flaws. Multiplayer had some great improvements, some great maps, some major issues, some terrible maps...
Black Ops: Single player is terrible, not even worth the effort it takes to play it. Multiplayer fixes a number of the major issues with MW2's balancing but is hampered by worse performance (PS3) and worse maps overall. However it does have Zombies...
Reach: An amazing single player campaign, well not setting a standard of story telling really creates the perfect atmosphere. Multiplayer is pretty great but doesn't really appeal to me on the same level as COD
I don't know...I think I'll give it to MW2 since I played it the most and it has Terminal my favourite multiplayer map
