I love a good podcast! I tend to listen to true crime ones (thanks to Serial series 1, which is still hands down the best podcast ever!).
So:
Serial (I didn't get on with S2, but S3 has just started and sounds promising)
My Favourite Murder (LOVE this)
Teachers Pet (just finished this, it was VERY repetitive, but a good, if very sad, story)
Adam Buxton (when I need something more light-hearted)
This American Life (although I've gone off this one a bit)
Stuff You Should Know (good for all the family - we often listen to these in the car)
You Must Remember This (Hollywood stories - the Charles Manson one is good, but grizzly).