Running out of Security Now! and TWIT episodes, I have subscribed and started listening to few newly discovered podcasts.
I have started to listen to the .NET specific one from Scott Hanselman named Hanselminutes. There are couple of factors that makes it better that other geeky blogs out there. First reason is the content quality. There is very high signal-to-noise ratio, pretty much all content counts and both guys in addition to being smart are quite good at achieving right balance between keeping on topic and spontaneity.
Second reason - it is not technology-religious and quite pragmatic. Scott obviously likes .NET and is passionate about Microsoft technologies - but there is no sucking-up, Scott is very open minded - just listen to the Dynamic languages where they talk about Ruby on Rails. He even owns a Mac and tests multiplatform software on multiple platforms :-)
Third reason: there is PDF transcript available with lots of good links which would be otherwise lost (unless you listen with pen in your hand and in front of computer, and not driving or walking as myself.)
And last but not least - very good audio quality, professionally recorded and processed. After listening to this episode about professional audio processing, it was clear why. Episodes are reasonably short - 20 to 40 minutes
I have learned quite a lot from the about variety of interesting things - e.g that WPF/E (recently named Silverlight) may be actually something I really want to look at :-). It almost sounded too good to be true.
So if .NET is part of your world - or you want it to become part of your world - go for HanselMinutes.