Dan Carlin's Hardcore History, Revolutions + History of Rome, Land of Desire (a remarkably talented hobbyist show on French history), Patrick Wyman's Tides of History which is wrapping up soon after about a billion episodes, American History Tellers, History of India... there's a show for everything, but I think you have to try a few to get a feel for how granular you like and what sort of style calls to you.

And I find podcasts gradually lead me towards books. It's just harder to read a book while walking my dog.