The Great Courses vary wildly in quality because it all depends on the lecturer. I prefer the DVD versions to the audiobook versions, generally, because some lecturers use maps or photographs and because some of the DVD lectures are captioned. Each course comes with a book containing lecture transcripts/notes.

I haven't had good luck with lecture series covering subjects beyond literature and history. I suspect that's me rather than those other courses being bad. I had trouble paying attention.