The Great Courses - lectures packaged by the Teaching Company - have been the focus of a few of my blog posts. Be sure to peruse their website; you're certain to find something that interests you.
Aside from the pure educational value, i.e. learning about the subjects, I've recently detected an ancillary benefit of continually listening to world class scholars - a clear improvement in the precision of my language, spoken and written. Each time I notice these experts tease apart a distinction, I try making a mental note. For example, what separates an important contributor to their field - be it philosophy, music, dance - from an influential one? Frequently, my dictionary is the first book I consult soon after listening. That alone makes the whole experience rich.
In addition, almost without exception, the lecturers are careful with their superlatives, a useful model to follow. If nearly everyone is a genius or a revolutionary or amazing, those words lose currency. If more precise writing or speaking is at all important to you, what tools do you find as helpful as I find the Great Courses?