Some of the ones i have enjoyed listening to lately.

Debug (http://www.imore.com/debug): Interviews with interesting people in tech. Several of them with former Apple engineers.

The Infinite Monkey Cage (http://www.bbc.co.uk/podcasts/series/timc): Panel discussion show hosted by physicist Brian Cox and comedian Robin Ince with guest Scientist, Mathematicians and Comedians. Both entertaining and interesting.

Sill Untitled: The Adam Savage Project (http://www.tested.com/podcast/still-untitled-the-adam-savage...): The podcast is hosted by, among others, Mythbusters host Adam Savage. The show covers a large variety of topics but always seems to land on something that interests me.