Letter from America�also shows up on the BBC World News sometimes - WNYC plays it for a few hours at over night.
I absolutely love "Wait Wait Don't Tell Me, The NPR News Quiz" - my thumbnail has been their logo for a few weeks now.
In addition to what other people mentioned, I'm going to add:
The Next Big Thing - a WNYC culture magazine that was recently picked up by PRI
Bill Radke's Radio Rewind - "a not so serious look back at the week in review" was recently dropped by PRI, and is now only broadcast locally around Seattle, in a call-in-show format.�
Definitely Not The Opera - The CBC Radio One show that I never would have known about had Rachel Barecca not done a documentary about Frucon IV for them.� Jian does entertainment reviews, but they're never part of the "DNTO on Demand" archive on the website, so you have to catch it broadcast on Saturdays.� Luckily, since Canada has so many time zones, if you miss it on Radio One Halifax you can catch it on Radio One Winnipeg!
ThirdcoastFestival.org is Chicago Public Radio's collection of International radio stories.� Radiolab is WNYC's similar project.� I learned about ABC through them, and sometimes listen to their programmes.
On The Media is a news-watching news program that is way way waaaay more interesting than their name suggests.
If you can't tell, I adore Radio shows.�