The professors are almost always excellent and enthusiastic. Over the many years there have been only two of the courses that I found disappointing, which is a very good track record since, as a teacher myself, I tend to have very high standards. However, LOOK FOR THE SALES, some of the courses can be expensive but yearly they have fantastic sales.

https://www.amazon.com/The-Teaching-Company-Great-Courses/product-reviews/B00CYNPAEC