I listen to Extra Hot Great, Pop Culture Happy Hour, Slate Culture Gabfest and How Was Your Week each week. Julie Klausner's monologues are unique and a lot of fun, and she's had some great guests (I've chosen some recent my non-fiction reads based on her interviews, including Columbine and The Psychopath Test).
I thoroughly enjoy the Nerdist Writers' Panel with Ben Blacker, even though I'm not a writer.
Nerdist, Marc Maron and Jeff Garlin are guest specific for me, but I don't listen to Maron's monologues. The Tig Notaro episode of Garlin's By the Way had me in tears laughing for a good portion of the interview.
Speaking of laughing until you cry, I would listen to Tara, Dave and Pamie talk Hawaii any time, and wish their "She Loved Bamboo" podcast were still available online.