I Was There Too - interviews with smaller players (generally extras or supporting cast members) involved in iconic movies. Interesting, personal perspectives and a charming, funny host. Among many others, highlights have been Stephen Tobolowsky talking about his role in Groundhog Day (Bing!), Jenette Goldstein talking about playing Vasquez in Aliens and comedian Greg Proops being delightfully frank about his experience on The Phantom Menace.
The Flop House - there are dozens of 'bad movie' podcasts, but this is the best one I've found. Hosted by one current and one former The Daily Show writers (and their bartender pal who is arguably the funniest of the bunch), its perhaps an acquired taste, but it routinely makes me laugh more than any other podcast.
Retronauts - Retro videogame podcast. Sometimes the subjects can be a little niche for me (they just did a very thorough examination of the Apple II, for example), but when its a topic I'm interested in it's a great listen.
Cane and Rinse - it's awful name aside, this is the best videogames podcast out there. Thoughtful, intelligent dissections of some of the biggest and best games of the medium's history. Zero snobbery - a simple mobile game like Threes! gets the same level of attention and discussion as GTAV. The back catalogue is a treasure trove.
Thirty Twenty Ten - a great concept (a pop culture deep-dive into the biggest songs, movies, comics, videogames and sometimes news stories from 30, 20 and 10 years ago the week of recording) executed brilliantly. Some proper nerding out that occasionally unearths some really interesting trivia nuggets, long-forgotten pop culture artifacts and unlikely coincidences across the decades. I also like all the other output from the guys who do this show (Laser Time), though it's a mixed bag - sometimes a little US centric and with a slightly tedious preoccupation with professional wrestling.
Distraction Pieces - which is hosted by Scroobius Pip, who I like a lot. Topics and guest vary wildly with some (again to my tastes tedious) digressions on wrestling and UFC). But when it's good, its great. Pip is such an engaging and sensitive interviewer that he can really draw a lot out of his subjects, and even episodes that you might think would be not particularly interesting can be really raw and illuminating - see his two part interview with TV presenter Gail Porter.
No Such Thing as a Fish - aka the QI podcast. Love this one, though I don't tend to listen weekly and prefer instead to stockpile them for road trips.
I also dip in and out of The Joe Rogan Experience. As with others, your mileage may vary depending on guest and subject - and Rogan himself is a pretty opinionated, divisive figure - but I'd highly recommend the recent episode with Scientology whistleblower Leah Remini - it's pretty explosive stuff.