Stuff You Should Know -A show that originally came from How Stuff Works. The name is self explanatory
Radiolab -A science based narrative type show that originally airs on WNYC, a major NPR Affiliate and it used to be my favorite show but it's gone down in quality in recent years.
It's Always Sunny Podcast by the cast of Sunny in Philadelphia talk about their shows and personal lives. It's arguably the most light-hearted show I listen to
Philosophize This -a educational podcast that discusses mainstream philosophy and the development of the subject in chronological order. I'm only 29 episodes in and there are currently over 200
99 Percent Invisible -A show about the world of design and the stories behind it narrated by the perfect voice for radio, Roman Mars
The Dollop -An American history dark comedy podcast by comedians Dave Anthony and Gareth Reynolds
The Weekly Show with Jon Stewart -The current iteration of Jon Stewart's podcast where he speaks much more candidly and at length on current events, mostly politics
NPR's Marketplace -a daily radio show on the state of the economy as well as markets
Marketplace presents: The Uncertain Hour -A podcast that does season length stories that take a deep dive into the broken aspects of americas economy, america's failing regulation & safety nets.
Behind The Bastards -A Biographical podcast about a lot of historic/prominent people that probably shouldn't be idolized
Sawbones -A podcast about the history of medicine.
The Moth -A collection of personal stories of triumph, change, growth, and inspiration as they were remembered and told live on stage. I first heard it on NPR.
On a more personal level I also listen to various collections of Alan Watts talks in addition to Sam Harris's Making Sense podcast.