Easy Black Ops 1,
Black Ops 2,
World at War (would be higher if its maps werent re-released all the time),
Black Ops 4,
Black Ops 3
(both 3 and 4 were pretty bad but 4 is higher because i actually enjoyed Classified as a remake)
favorite maps are any of the black ops 1 maps, Mob of the Dead, Origins, and Classified but i still have fun with any map