I always recommend Byzantium and Friends. The host might not be a Marxist but he’s as close as you can get (an entire episode explicitly condemns the neoliberal influence on academia), and there’s just so many fascinating episodes about aspects of Byzantine life I had never known about before. It’s really good if you want a break from the usual doom-and-gloom, since Byzantium was destroyed 600 years ago and most people have accepted that.