The 20 best TV documentaries – ranked

• Drama is sexier, comedy more quotable, current affairs more immediate, but the very finest documentaries sit unquestionably among the most important television ever made. True stories sometimes told straight, at other times tweaked, subverted or filtered through a new lens to offer a fresh perspective. Frequently changing the way television was made, they have covered a limitless array of subjects from warfare to the arts, celebrity to politics, but their most powerful moments often focus on the