Ask HN: What lectures or lecturers do you watch?

I began watching some videos of Stanford Professor Robert Sapolsky and have fallen in love with his style. The topics he teaches aren't anything I'd normally be interested in, but he is an excellent and interesting speaker.

In the spirit of expanding our knowledge, I hope to hear back from the Hacker News community about the lectures or speakers you all find interesting.

Sapolsky's lecture on depression in the US [0] got me hooked and now I'm working my way through his Human Behavioral Biology class[1], which is also excellent.

[0] https://www.youtube.com/watch?v=NOAgplgTxfc [1] https://www.youtube.com/playlist?list=PL848F2368C90DDC3D