Confession: for a guy who hosts a podcast, I don’t listen to all that many of them. I used to enjoy 99% Invisible, and I still recommend it. But for me, it doesn’t go into quite the depth I prefer for the medium. Others do go into quite a bit of depth, but get bogged down by (often political) dogmatism and pettiness from the host.
I’ve recently become enamored of the physicist Sean Carroll. He works primarily in cosmology and is known, among other things, for being a strong proponent of the many-worlds interpretation of quantum mechanics. However, he’s also a generally curious guy with broad intellectual interests.