Call of Duty 4: Modern Warfare\n\n It's at the top of the tier list for the series' games for a solid reason. The first Modern Warfare revolutionized both the approach taken by COD as well as that taken by just about every other FPS game.

Black Ops Cold War is surprisingly the shortest Call of Duty game at just over 5 hours. Despite its length, it has a memorable campaign with rich and detailed environments.