My preference in roughly the following the order:
1) Local sports talk (not the nationally-syndicated shows.) Some of them are good, but I've never been a huge fan of syndicated radio. I prefer local flavor when it comes to radio. But if they're not talking about something I enjoy (and this is the slowest time of the year) then . .
2) Podcasts. Usually more tech-oriented shows like TWiT, BuzzOutLoud, DL.TV, etc, but I also have a few more comedy-oriented podcasts I like.
For commuting and having to deal with traffic I personally find talk (be it local sports radio or podcasts) more relaxing than music. It helps pass the time better and keeps me nice and calm.