I went through this thread and tallied up all the mentions, agreements, etc. -- here are the top 20 results:

Startup (11 mentions) - http://gimletmedia.com/show/startup/

This American Life (10 mentions) - http://www.thisamericanlife.org/podcast

99% Invisible (9 mentions) - http://99percentinvisible.org/

Radiolab (9 mentions) - http://www.radiolab.org/

Planet Money (8 mentions) - http://www.npr.org/blogs/money/

Invisibilia (7 mentions) - http://www.npr.org/programs/invisibilia/

Serial (7 mentions) - http://serialpodcast.org

Bugle (6 mentions) - http://thebuglepodcast.com/

Dan Carlin's Hardcore History (6 mentions)

EconTalk (6 mentions) - http://www.econtalk.org/

WTF with Marc Maron (6 mentions) - http://www.wtfpod.com/

Freakonomics (5 mentions) - http://freakonomics.com/category/freakonomics-radio/podcasts...

Skeptic's Guide to the Universe (5 mentions) - http://www.theskepticsguide.org/

Moth (4 mentions) - http://themoth.org/

No Agenda Show (4 mentions) - http://www.noagendashow.com/

StarTalk (4 mentions) - http://www.startalkradio.net/shows-archive/

Startups for the Rest of Us (4 mentions) - http://www.startupsfortherestofus.com/

The Truth (4 mentions) - http://thetruthpodcast.com/The_Truth.html

Upvoted by Reddit (4 mentions) - https://itunes.apple.com/us/podcast/upvoted-by-reddit/id9541...

Anything else was three mentions or less, but I'll likely put my spreadsheet up on Google Sheets.