+1 for Econtalk. Despite the name, the podcast is not about the (relatively boring) econ theory, or even the direct application of it. Econtalk uses economics in the same way as "Freakonomics" - as a framing device to talk about incentives, complex systems, and far reaching effects that are not obvious on the first pass.

I find Econtalk discussions meaningful and rigorous, in contrast to carefree series like "99% Invisible" / Invisibilia / Startup. The latter are great as a chewing gum for the brain, but they are mostly trivia and I do not recall learning anything useful from them over the years.