I always thought documentaries to be boring and that changed after watching - Icarus (Netflix): about state-sponsored doping scandal in Russian Olympics teams - Amazing!
Now I want to explore the world of documentaries, on any topic; I just want to expand my worldview.
I'd recommend "Jiro Dreams of Sushi" on Netflix. It's a really interesting look into the mind of someone seeking perfection and mastery of their craft.
All documentaries by: Scott Noble (available free at his site http://metanoia-films.org/), Patricio Guzman, Werner Herzog, Adam Curtis, The Yes Men.
Other great documentaries: Man with a Movie Camera, Sherman's March, Burden of Dreams, Bus 174, My Winnipeg, How to Start a Revolution, Merchants of Doubt, Silenced (2014), the Corporation (2003), Man on Wire, The Parking Lot Movie, Land of Look Behind, Intangible Asset No. 82, Brasileirinho, Jodorowsky's Dune, Revolution OS, Facebookistan, The King of Kong, Kumaré, McLibel, Harlan County USA
Why? Because they're amazing, important, will change your life etc. Sorry I don't have hours to go into detail. Enjoy!
ps I found a lot of these by googling best documentaries lists, IMDb lists etc. I judge whether to watch movies/docos by reading 2 or 3 pages of user reviews on IMDb, occasionally Ebert or Urban Cinefile etc also.
I recently saw one called "What the health" and "in defence of food" (better) about how USDA is in bed with The meat, egg, sugar and pharma industry and how their guidlines are just plain wrong if not harmful.
I've been reading about this lots and lots to the effect that I've reduced my non veg intake to once a week and yes my health has improved a lot since too. But ymmv and it's definitely worth a watch even if you don't agree to hear their viewpoints.
Incredible insight into the current geopolitical climate and how actions in previous years have had huge ramifications to what's happening now.
https://en.wikipedia.org/wiki/HyperNormalisation