Hoop Dreams (1994) - Explores inner-city poverty through the eyes of two young boys in Chicago who want to use basketball as a way to escape their environment. I haven't seen it in a long time, but my biggest takeaway from it is how narrow the bridge to "success" can be for some. If you grow up in a well-to-do upper middle class environment, you can make a shocking number of youthful mistakes, yet still get saved by your parents, school, society. Others really only have one or two chances to make things work.
The Kingdom of Dreams and Madness (2013) - A must-watch if you're an admirer of Hayao Miyazaki movies. Goes into his creative processes; how he thinks about his work, the world at-large, etc.; and his long-standing friendship with his producer, Toshio Suzuki.