There was once a time when the main draw to the newest Call of Duty was its dramatic single-player campaigns. But, over the years, as broadband connections became commonplace, the focus shifted to online multiplayer, and that's where most players start their journey each year. But for those of us who still appreciate the bombastic campaigns and the stories they tell, there's a decent back catalog of thrills to get stuck into. Here are the ten best Call of Duty campaigns, ranked.