ANNcast is the only podcast I listen to every week without fail. Zac and Justin's knowledge of not only anime, but the operations of the Japanese and North American markets is so far beyond most other podcasts, and it makes a huge difference. They also always offer wonderful, specific critiques of current and past titles. Their reviews are not summaries, as are those of so many other podcasts - they know how to review without spoiling (that is to say, they know how to review). The guests they bring on are similarly informed, and often times they will bring on industry guests, something most other podcasts cannot boast. When I turn into ANNcast, I know I'll be getting informed, well-reasoned commentary, analysis, and reviews, and I couldn't ask for anything better. It's been a great four years, guys, and here's to many more!
Oh, and Zac's sarcasm is wonderfully snarky. I don't care what anyone says.