The Teaching Company is adding lectures at quite a fast rate. I used to be able to say I had seen almost all of their science courses but they have added new offerings faster than I can watch them in the past year.
I wrote about some of my favorite lectures in science and in economics earlier (see Great Lectures from The Teaching Company).
I am watching Thinking about Capitalism by Jerry Muller right now which is excellent but mostly for people who want to know the history of economics. The genius of Adam Smith was really unbelievable – he foresaw a lot of the things we still argue about today.
I have not watched Economics 3rd Edition by Timothy Taylor but he is such a good teacher I might want to watch it.
In the science realm the best is probably Physics in Your Life by Richard Wolfson. He explains everything very clearly and his description of how semiconductor chips work is the best I have ever seen.
There is a great biology course (Biology: The Science of Life by Stephen Nowicki) and a great physics course (Particle Physics for Non-Physicists: A Tour of the Microcosmos by Steven Pollock) but those are pretty in-depth and designed more for people who want to learn the field.
Another great hard-core course is Understanding the Universe by Alex Filippenko. It is a total of 48 hours and is more in depth than most people need, but if you want to understand astronomy, there is no better way to learn it.
There is a six hour course called Earth’s Changing Climate, also by Richard Wolfson, that I recommend to people who want to learn about the science of climate change.
In medicine there are two that I like a lot. One is The Human Body: How We Fail, How We Heal by Anthony Goodman. He explains the different diseases that people get and the progress we have made on how to treat them. The other is Sensation, Perception, and the Aging Process by Francis Colavita. He takes all the senses and explains how they work and how they change over time.
There are two lectures on linguistics by John McWhorter that I really loved—Understanding Linguistics: The Science of Language and the Story of Human Language. The history of language is far more interesting than I thought it would be—in fact it is fascinating.
The only religion course I watched was Comparative Religion by Charles Kimball. It is excellent.
In math, the best general course I’ve seen is Joy of Thinking: The Beauty and Power of Classical Mathematical Ideas by Michael Starbird and Edward Burger.
The category which I have not gone into but I expect to someday is "Fine Arts and Music.”
For a long time their best selling courses were the Robert Greenberg lectures on understanding music.