I like Basic Brewing Radio by James Spencer. I don't listen to every podcast, but I have learned from it.
I also subscribe to Good Beer Hunting. It typically features a brewery that they talk with. I don't listen to every one of it either, but some of them have been fun.
The last beer one is Homebrew Happy Hour. It's a little more light-hearted. Some of the guys are goofballs, but it's a real fun listen. It's sponsored by Kegconnection.com, so it smells like a commercial at times, but it's informative.