If you drive a fair amount and have an ipod, it's essential that you visit radiolab and see what they've been up to.
You can easily (and for free) subscribe to their podcast in iTunes and listen to every one of their past shows. I'm hoarding them, saving each one for a drive that deserves it, because they don't make new ones fast enough.
The content of each show is a unique mix of science, pop culture and relevance. I guarantee that they will make you smarter. That's a lot to promise for a radio show, but I think it's true.
And the production demonstrates that even when a medium is 90 years old, it's possible to reinvent it. They make the flat and linear structure of radio old fashioned. These guys are the real deal, and I'm privileged to recommend them to you.