I've been a follower of many WoW podcasts since teh early days of WoW and the majority have faded away either because the show stopped or the host(s) stopped playing WoW.
Over the years though the general trend has been a steadily increasing quality of production and some great content too. My current list is below in alphabetical order because sorting into a ranked order was just too tough:
All Things Azeroth One of the oldest WoW podcasts with roots back to 2004 it is the podcasts with most episodes too. The show is a general WoW news show and hosted by Medros, who is not a raider and focuses on the more fun activities, and new co-hosts Rho and Nananea who recently replaced long time co-host Shade. A great starting point.
Convert to Raid Want a weekly fix of raiding news and views? Look no further than Convert to Raid, the award winning weekly podcast for raiders in World of Warcraft. Convert to Raid also covers boss strategies, player guides and discussion, and really bad jokes. If it’s in the end game, it’s on Convert to Raid! The production quality of the show is high.
Group Quest From the same stable as All Things Azeroth, the show is a round table type discussion show hosted by a what I assume are a few geeky guy in their early 20s and at times can be a bit immature and they do suffer from occasional poor sound production quality. That said their content is good and they do discuss some topics that the other shows fail to cover.
The Instance The number 1 most listened to WoW podcast and has over 300 episodes. It is also definitely one of the best and is focused at a level most players can relate to from newbie to hard core raider. It is a podcast for lovers of World of Warcraft. Hosted by Scott Johnson, Turpster, and Dills, The Instance is home to the latest news, rumors, and people from the thriving WoW community.
My Epic Heals As the name suggests this podcast is about all things healing in the World of Warcraft. Adobe (Shaman), Buck (Priest), Eade (Paladin), Pitango (Monk), and Wolfshade (Druid) give a perspective from each healing class in the game. This is not a “breaking WoW news of the week” type of show, but rather a roundtable style discussion among skilled yet humble players.
Rawrcast co-hosted by Stomp and Haf a real life couple they cover game-related topics, news, opinions, and reviews. You can tell from listening to them that they are a fun-loving couple who wear their hearts on their sleeves. The only negative about the show is that they are not particularly family friendly but that isn't something to put you off listening to this awesome podcast.
The World of Warcast a podcast dedicated to teaching listeners about how to play World Of Warcraft they cover many topics from playing a new character, to raiding at endgame, playing different classes, different races, different professions. Despite being one of the longest running WoW podcasts it has only recently surpassed 125 episodes and that is the biggest issue I have with this podcast tehy are simply too irregular.
And some you should have listened to before they went away