I enjoy just about everything knuck put up, so second all that...I also do the ESPN podcasts - Around the Horn and PTI primarily.
Some others:
Serious second to Planet Money
How to Do Everything
The Moth
Still Untitled - The Adam Savage Project
Stuff You Should Know
How to do Everything
Also - I don't really recommend iOS's native podcast app. It's not great, and they haven't really tried to improve it because there are some really really fine podcast apps out there. Overcast hit with a big splash a few months back.
https://overcast.fm/ It's free with paid features - I bought the whole thing - I see why people like it - it's really good for podcast discovery it. It's not for me though - one nice thing about it is that in an effort increase podcasts in general, the app provides links to all of it's competitors that have a slightly different take on the podcater.
I've been using Downcast for several years now - I REALLY wanted to like Overcast, but I navigated back to Downcast. It's a bit grittier, but lets me do a bit more fine tuning - plus it's just more comfy for me.
http://www.downcastapp.com/ Highly recommended.