I listen to a lot of podcasts. I have about an hour long commute, and I also enjoy listening while I write code. All of the podcasts listed are available for free in iTunes. Hardcore History is the only one who charges for back episodes, only the latest 10 are available for free. It's completely worth it for the amazing content he produces though.
The Joe Rogan Experience
This is an amazing podcast. Joe Rogan, yes the guy from fear factor and UFC spends 3 hours with a guest - sometimes comedians and sometimes an expert in their field, and they just talk. I usually dodge the ones with just comedians, because 3 hours is a big commitment.
The Infinite Monkey Cage
This one is new for me, and I actually found out about it from the Joe Rogan Experience when Professor Brian Cox was a guest. Brian Cox is a physicist and a philosopher which is an epic combination.
In Our Time with Melvyn Bragg
This one is put on by the BBC and goes into tons of different topics from Bertrand Russell to Game Theory.
Hosted by a Neuroscientist, Indre Viskontas, this podcast explores tons of different scientific findings.
I think everyone who has listened to a podcast has listened to this one. It sucks you in, and keeps you there.
The Time Ferriss Show
Mr. 4 Hour Work Week himself proves out why his books have been so popular and engaging. This one is great, and there are some amazing guests.
Financial Independence Podcast
The MadFientist himself! If you are familiar with Mr. Money Mustache, this guy is like his evil scientist counterpart who does gritty math to determine the best routes to financial independence. This isn't updated much, and the quality is shit but its good content.
This Developer's Life
It's like This American Life for Software Developers.
This is for programmers who have thoughts in the back of their head about one day being an entrepreneur.
Dan Carlin's Hardcore History
This is my favorite podcast. There's only about 1 new episode a month, but I wait for it because it's absolutely fantastic. I think Dan must go out and read 50 books on each topic he picks, and after he digests the material he regurgitates the best stuff. My two favorite series were Wrath of the Khans and Death Throes of the Republic.
Common Sense with Dan Carlin
It's really hard to get information about politics these days without hearing an agenda, either right or left. The whole damn thing has become so polarized, but Dan once again shines with this podcast. I call his political philosophy centrist.