Andrew and I just decided to get Netflix (this is not a product plug) last Saturday and it's been a documentary marathon ever since.
Among my favorites are Food Inc, Tapped, Future of Food, Dirt! The Movie, Homo Toxicus, All in This Tea, The Cove, King Corn, Freakonomics, Cracking the Maya Code, Beer Wars, Secret Yosemite, Hiroshima:BBC History of World War II, and To Market To Market To Buy a Fat Pig. Notice the overall theme.
If you haven't seen 'The Cove', it is by far the saddest movie I have ever seen. I had tears in my eyes through the majority of it. It was an extremely well done film.
The Future of Food was great because it broke down some of the science behind GMO's.
All of these film's had a lot to teach. Perhaps you will enjoy some of these as well.