1. Black Ops II. Call of Duty: Black Ops II took everything that Black Ops did right 😊 with the Zombies mode and perfected it even more. No one thought this would have even been possible, but Black 😊 Ops II created the perfect and best Call of Duty Zombies mode of all time.

Call of Duty: World at War is 😊 considered the hardest game in the series, with intense enemy presence, constant fire, and challenging missions that make it the 😊 ultimate experience in terms of difficulty.