The lectures of Nobel Prize winning physicist Richard Feynman were legendary. Footage of these lectures does exist, but they are most famously preserved in The Feynman Lectures. The three-volume set may be the most popular collection of physics books ever written, and now you can access it online, in its entirety, for free.
Well known for his work in quantum physics, Feynman won the Nobel Prize in 1965 for his role in developing Quantum Electrodynamics. His work influenced many other physicists of his day and countless scientists since.