Richard Feynman was famous for his engaging physics lectures. 

Some 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.

The complete online edition of The Feynman Lectures on Physics has been made available in HTML 5 through a collaboration between Caltech (where Feyman first delivered these talks, in the early 1960s) and The Feynman Lectures Website. The online edition is "high quality up-to-date copy of Feynman's legendary lectures," and, thanks to the implementation of scalable vector graphics, "has been designed for ease of reading on devices of any size or shape; text, figures and equations can all be zoomed without degradation."

Volume I deals mainly with mechanics, radiation and heat; Volume II with electromagnetism and matter; and Volume III with quantum mechanics.

Go. Have fun: http://www.feynmanlectures.caltech.edu/

Watch a series of seven brilliant lectures by Richard Feynman on io9