In my opinion the best internet audio talk show for .NET developers:
".NET rocks" was one of the first podcasts, when podcasts weren't being called podcasts. So listen to this .net podcast.
Here is a brief description from the site:
.NET Rocks! is a weekly talk show for anyone interested in programming on the Microsoft .NET platform. The shows range from introductory information to hardcore geekiness. Many of our listeners download the mp3 files and burn CDs for the commute to and from work, or simply listen on a portable media player.