Maybe my #1...
Alone in the WildernessI love watching him work. His precision with a couple simple hand tools is SICK. Need a mallet? Build it. Need a chimney? Build it. Need a door? Build it.
I first saw this as a young teenager. It really brought out the DIYer in me. Taught me the value in building things yourself. The personal satisfaction that comes with working with your hands. I mean I always kind of knew there was value, but this made me respect it and understand it. On top of that Dick has a lot to say about life, but not in a know-it-all way. He's not looking for the meaning of life or anything so grand, but he's come to his own humble conclusions and it's wonderful to listen to him talk about them as you watch him build his cabin.
Anyways, it's worth seeking out the full doc.
I second matt's choice: Cesar's Bark Canoe (Bernard Gosselin, 1971). Watched it not long ago after he mentioned it elsewhere. I enjoy it for similar reasons.