Do tell me more. I've been looking for one of those for when I run out Nightvale.
Hardcore History mostly focuses on times of war and turmoil (fall of the Roman Republic, the Mongol invasion, etc.) - Dan Carlin's a good storyteller, and he always brings a pragmatic point of view that I find refreshing. For example, he has one podcast where he talks about the atomic bombing of Japan. We've all heard the old chestnut about how it was better than doing a land invasion, but Dan couches it in the larger narrative of strategic bombing throughout time: how people feared bombing practically from the moment flight was invented, to early stabs at military aviation during WW1, to the "trial run" at Guernica, to the horrors of fire bombing in Tokyo and Dresden. It's a very powerful podcast, and it effectively conveys the message that all warfare, not just atomic warfare, is madness.
The Thomas Jefferson Podcast features a guy roleplaying as Thomas Jefferson and answering viewer questions. No, it's not ERP. It's well-researched and does a good job of putting you in the shoes of the Founders. You become privy to the minutiae of our national heroes' lives, something that lets you put their actions in context. For example, it was very interesting to learn that TJ was bookish and reserved and fascinated with gadgets and experiments. Between all the money he spent on books and the way he wanted music all the time, you really get the sense he was born in the wrong era.