Although it may play very differently in MW3, Bog, Downpour, and Ambush were my 3 favorite COD4 maps. Although, if I had to pick one, Bog was the only one that actually made me giddy with excitement when it came up.
A lot of people hated it, but one of my favorites in MW2 was Wasteland.
Im going to say...Cod: FH- Factory(I think that was the name) Cod: BRO Breach Cod3:Eder Dam Cod4: Broadcast ( Wish this comes back one day) Waw": Asylum mw2: Terminal BO: Launch(The rocket) mw3: That one map. So thats a map from every cod game ive played.