Several of these show up on Connor's list too (that's where I was introduced to them in the first place), and they're well worth mentioning again.
The DollopDavid Anthony and Gareth Reynolds
Two comedians discuss obscure and absurd American (and sometimes Icelandic or Australian) history. Lots of interesting and gameable things here, and a certain amount of zen that comes with the acceptance of the perpetual insanity of the world. [GOLD STAR]
SequelisersJack Chambers, Stuart Ashen, Alec Plowman, Matthew Stogdon, Tim Maytom
Four British men propose re-writes of bad sequels to good movies. Played as two teams competing against each other for the completely arbitrary favor of the judge. The end results are always interesting, with plenty of left field curveballs to go along with the more true-to-the-original pitches.
Blogs on TapeNick Whelan
Fun, interesting, and useful blogposts from the OSR / DIY RPG community for your listening pleasure.
Bad Books for Bad PeopleTenebrous Kate and Jack Guignol
Do you like people talking about horror-gothic-weird-sex-stuff books, and occasional other books? Good, they do that. It's fun.
The Magnus ArchivesRusty Quill
A god-damn excellent horror serial series. Spooky stories, intricate metaplot, excellent acting, a mythos ripe for exploration, and a plan to see through things to the end at episode 200. Top marks, an absolute must-listen. This will not be the last time I talk about them. [MANY GOLD STARS]
Science & Futurism with Isaac ArthurIsaac Arthur
An actual rocket scientist talks about big picture concepts in space exploration, colonization, the Fermi Paradox, and more. Absolutely worth a listen if you're in the mood for some more optimistic ideas of future technology, or really feel like some mind-bending huge scale. It takes a little bit to get used to Isaac's speech impediment at first, but you get used to it soon. [GOLD STAR]
GastropodCynthia Graber, Nicola Twiley
Fun food history and science. Always puts you in a good mood, if a hungry one.
TFS Bento: Anime FMKKirran, Scott Frerichs, and Ben Creighton
Three guys watch a bunch of anime that no one has time for, and sort out the chaff from the good stuff. Actually works decently well as entertainment with no context at all for the shows in question, but I might be an outlier on that.
Heaven's GateGlenn Washington
A detailed and empathetic look at the Heaven's Gate cult, from inception to end. A fantastic documentary. Don't take the lack of words here as lack of content, it is fantastic [TWO GOLD STARS]
Journey to ZyxxAudioboom
Improv sci-fi comedy, right in the Star Wars / Star Trek / Hitchhikers'. Great for a laugh. 18 episodes, season 2 will be coming along soon enough. [GOLD STAR]
LeVar Burton ReadsLeVar Burton
The man himself reads his favorite short stories. Loads of great sci-fi and fantasy here. Further explanation unnecessary. Start with "The Second Bakery Attack" if you want a blind jump-in point [GOLD STAR]
The DiecastShamus Young and Paul Spooner
A laid back show about games and programming. Lots of letter-bag segments, occasional themed episodes. Easy listening, good if you like programmer dads being chill.
The Foreign BeggarsTabletop Twats
An excellently edited and acted two-man DCC adventure. Hilarious and great listening, irregular uploads but lots of care given to presentation. [GOLD STAR]
Role Playing Public RadioRoss Payton et al.
High-quality APs of a variety of games. Lots of Eclipse Phase, Base Raiders, Call of Cthulhu, Delta Green, Red Markets, and one-offs. The recent Zweihander episode and "Somewhere Lane" are some of the best APs I've ever listened to.
Film RerollPaulo Quiros and many other people
Famous movies are played through using GURPS. Shenanigans ensue as scripts are thrown right out the window and movie logic is overturned.
Orpheus ProtocolRob, Staci, Dan, Jhan
Long-running AP of the game by the same name. Lots of weird magical-horrific conspiracy stuff going on (this appears to be a theme in my picks). The GM knows what he's doing when it comes to slow burns, unsettling imagery, and cranking up the nightmare fuel
Not Actually Podcasts
Down the Rabbit HoleFredrick Knudsen
A look into bizarre and forgotten corners of the internet and unsettling stories that have slipped through the cracks of memory. Deep well of gameable material.
Game Maker's ToolkitMark Brown
In-depth, but approachable, discussions on specific mechanics in video games and how they work. [GOLD STAR]
Like I said: A LOT of podcasts...