For International Workers' Day, as it's known in most of the world, let me commend to you Park Kwang-su's 1996 biopic of the South Korean labor activist Jeon (or Chun) Tae-il, who in 1970 immolated himself as a protest against the oppressive and illegal conditions in the garment sweatshops of Seoul.
A Single Spark was my introduction to South Korean film. A Korean friend, a student at IU, rented it on VHS from a local Oriental grocery to show me. He told me it was important for me to see, and he was right. I'm very grateful for his guidance. The videotape had no subtitles, and my friend interpreted for me -- not just the dialogue, but the history and politics, about which I knew little at the time. I later learned that the film had been partially crowdsourced; if you watch to the end credits, you can see a long list of contributors.
Later, I read the biography of Jeon Tae-il that had inspired the movie. It was translated into English by Jeon's sister Soon-ok, who after his death went to university and became a professor of Labor law. The Korean original was written in the 1980s, during the dictatorship, and circulated semi-clandestinely. The frame story of the film, involving a writer and his worker wife, is fictional, but on Jeon's life the story stays remarkably close to the book. It remains one of my favorite films. Eventually it was released on DVD in Korea, with some good extra features, but that, like the book, is out of print. I'm glad it can still be seen on YouTube.