I used to listen to a lot of them, but lately just two.
The 'The Good Friends of Jackson Elias'. This one is excellent. Primarily focused on The Call of Cthulhu RPG, but also Lovecraft and horror gaming in general.
Also, the 'Gaming and BS' podcast. No really deep insights, but I enjoy their thoughts and conversation.
Grognard Files, Plot Points, What Would the Smart Party Do? and Fear of a Black Dragon are the best rpg podcasts (in addition to the aforementioned Good Friends...). No rambling talk about their weekends and poor quality audio. Fictoplasm is also excellent but is as much a (very good) fantasy/sf book review podcast as a rpg one.
For some reason most of the best podcasts come from the UK.
I sometimes listen to Gaming and BS but at times they ramble on a bit too long where I would prefer them to just get to the point.
Save or Die, OSR banter and actual-play. I particularly enjoy the 30-minute actual-play session they currently have at the end of each show. Production is pretty rough, though.
Hobbs and Friends, OSR conversation and interviews.
Tales of Blood and Stone, Shadow of the Demon Lord actual-play with nice production.
Tales from Hyperborea looks good, though I haven't listened to a full episode yet.
I've listened to a few episodes of Spellburn, DCC-related discussion, but the backlog is huge and it's kind of a hassle to navigate. Production values are fairly low.
Ken and Robin Talk About Stuff, where "Ken" is Kenneth Hite, "Robin" is Robin D. Laws, and "Stuff" is . . . well, it's the sort of Stuff that Ken used to write Suppressed Transmissions about, only with Gumshoe replacing GURPS.
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