For me one of the best teachers you will find online
I watched those a while ago. They might seem really long at first but I can confirm that they are really good. I was fascinated by how much more sense our emotions and behaviour make if you learn a bit more about how the brain is wired and how it evolved.
Can confirm. These lectures are totally awesome. It is also possible to understand them only by audio, for example while driving.
Sapolsky is also a very entertaining writer! An excerpt from one of his books ("A Primate's Memoir") is here: http://www.npr.org/books/titles/138066966/a-primates-memoir#... , but my favorite excerpt from the book is that where he talks about tranquillizing baboons with a blow dart gun.