In each episode of Econ Talk Russ Roberts interviews a different intellectual figure about their specialty. He tends to do enough research beforehand that he can ask good questions regardless of the topic. Not every episode will be worth listening to, but his back catalog is a treasure trove of knowledge.
Dan Carlin is one of the few successful long-form media producers. The podcast is a cross between an audio essay and a tour-guide. There is plenty of historical information to gleam, but he also makes a significant effort to relate with the actual people who lived through it.
No Dumb Questions
Listening to this podcast is like overhearing a conversation between two friends. In fact, my favorite thing about it is how wholesome it is. They tend only to graze the surface of a topic, so I don't recommend episodes on things you're familiar with.
The Ten Minute Bible Hour
There are a lot of Christian podcasts. What I like about this one is the plain manner in which Matt presents the Bible. It appeals to my desire to not speak about my beliefs in such a way that only other Christians could understand.
What We Saw
The Apollo 11 and Cold War What We Saw series are my favorite audio essays. They achieve the rare combination of being dense in information and entertaining.
There is an unappreciated art behind mixing sound that this podcast helps reveal. I think this podcast would appeal to anyone that either enjoys mixing sound or wants to have a more critical eye for music.