I spend too much time listening to podcasts.
So I'll limit it to my top five.
I listen to podcast Oprah, aka Joe Rogan, though he posts so much content that I can't listen to all of his stuff.
Penn's Sunday School, I found Penn Jillette around when I found Atheism and the FSTDT front page in '04/05. Though some of his plant based beliefs might be close to Fundie now, he has a special place in my heart.
The Skeptics Guide to the Universe, three brothers and other Skeptics who have a science based podcast.
Dan Carlin's Hardcore History, awesome history podcast that updates like 4 times a year because of the research he puts into it.
And for all around silliness, Matt & Mattingly's Ice Cream Social. Las Vegas Improv duo who generally talk and be silly. Matt is a co-host on Penn's podcast, which is how/why I found them. I enjoy people who happen to be Atheists but the podcast has nothing to do with it.
Everything else is MMA, history, comedians, or fantasy.