Pretty heavy overlap with everyone else here but a couple I see no mention of:
Adam Ruins Everything: Basically interviews with experts in various fields that people have misconceptions about. Usually people that were on the TV show but much more informative than the show tends to be.
Futility Closet: Interesting and weird historical anecdotes. They try pretty hard to verify everything and most of the more detailed stories are in that "how have I not heard of this?" / "why is this not a movie?" category.