Horizon explores the discovery of the Omega-minus particle. After two years and thousands of photographs, scientists at Brookhaven National Laboratory confirmed the existence of a new particle which had a unique characteristic: "strangeness minus three."
This video is a great display of the excitement involved in scientific discovery as well as the philosophical and physical implications of natural symmetry in particle physics. Feynman in particular discusses this near the end of the segment.
This documentary contains interviews with Richard Feynman, Murray Gell-Mann, Yuval Ne'eman, and Nicholas Samios.