Ask HN: Feynman's Lectures in other disciplines?

I've been reading through The Feynman Lectures on Physics and I am really enjoying them. It almost reads like an internal conversation one would have with himself, while trying to understand a subject. It's logical, and detailed.

Do you know of similar study materials / lectures in other subjects: math, chem, bio ?

I understand they are obviously not going to be by Feynman, but I am looking for a similar approach taken by people in other disciplines.

Thanks!