[thinkr]

Wanted to add some other ones I did not see suggested:

Freakonomics Radio - by the authors of the book of the same name

Travel with Rick Steves - podcast by famous travel guide Rick Steves

Dinner Part Download - nice way to learn about interesting facts/random trivia/pop-culture regarding all sorts of subjects which can make for interesting conversation at your next social gathering

edit: meant to post this as a response to the question asking about other podcasts