Here's an e-mail I recently prepared for a friend:
Nerdery
Penny Arcade podcast - the penny arcade guys while they write the comic - hardly ever updates:
Downloadable Content, The Penny Arcade Podcast - Download free podcast episodes by Mike Krahulik and Jerry Holkins on iTunes.
ExtraLifeRadio - three dudes talking about nerd stuff - I really like it! They also do "The Instance" a WOW podcast - yucch!
ExtraLife Radio, with Scott Johnson - Download free podcast episodes by myextralife@gmail.com on iTunes.
A Life Well Wasted - Robert Ashley's radio program style show, kind of about gaming - really well done:
A Life Well Wasted - Download free podcast episodes by Robert Ashley on iTunes.
Comedy
You Look Nice Today - a few guys riffin' - I've really laughed at this sometimes, other times a bit bland, but try it!
You Look Nice Today - Download free podcast episodes by You Look Nice Today on iTunes.
Economics
NPR Planet Money - don't let the topic intimidate you - economics for the layperson - I wish I had discovered this earlier in my life... I'd have felt more prepared for dealing with my money and "getting" the economy (secret answer: it is all kind of crazy and senseless):
NPR: Planet Money Podcast - Download free podcast episodes by National Public Radio on iTunes.
Science
Radiolab - This will blow your mind - this is the radio show that most aspire to be like (2nd most) - be sure to listen to the full length episodes:
WNYC's Radiolab - Download free podcast episodes by Jad Abumrad & Robert Krulwich on iTunes.
Finally...
This American Life - the king of all radio/podcasts - a must hear:
http://itunes.apple.com/WebObjects/M...t?id=201671138
UPDATE: Extralife radio is now defunct! Scott Johnson decided to end the podcast in favour of his other ones (the Instance, etc.)