This one's a bit of a personal one:
Crown Lynn: A Maori Story
My Mum started watching TV randomly, then saw her grandad (my great Poppa - Joe Birch, around 5 minutes in) and her auntie Joan telling her story. I had never actually heard these stories before, so it was quite a cool thing to watch. A bit of NZ history, and nice to see Poppa again. He passed away when I was probably about 6 or 7, so I have met him, but mostly just remember him from a couple of photos. I never knew he was with Crown Lynn. I knew he worked at the brick works, and that his garden was built from bricks, but I just assumed he stole them - the Maori story :P