If you liked Restrepo, you would like Armadillo. It's about the Danes in Afghanistan, pretty kickass.
I loved:
The 30 for 30 series of shows about various sporting events and teams throughout the last 30 years or so.
Chef's Table - a set of 6 shows on Netflix about different chefs across the world, and their attitude towards food
Anything by Louis Theroux
World at War - Classic WW2 documentary narrated by the iconic Laurence Olivier. The best WW2 documentary ever made.
Stop at Nothing - a chilling look at the story behind Lance Armstrong's rise, fall, rise and fall again in the world of cycling. Really shows his dark side, and just what incredible lengths him and his team went through to cheat their way to the top.
The Smartest Guys in the Room - Documentary about Enron, and how the half a dozen people at the top of the tree ****ed over everyone who worked for them