Winner!

No doubt, by a parsec: Happy Jacks RPG Podcast, for which, not 2 weeks ago, I dedicated a happy birthday message (they turned 6!).

If I only had one RPG podcast to listen to for the rest of my days, this would be the one. Many compare it to hanging out (or more appropriately, drinking) with friends.

However, sometimes you just need something else... maybe for variety. Or more than likely because you've caught up on the voluminous backlog of HJRPG episodes.

Honorable mentions

So, let me give some honorable mentions:

Savage Worlds GM Hangouts Podcast: Jerrod ‘Savage Daddy’ Gunning and crew meet weekly Wednesdays to discuss Savage Worlds specifically, but GM-ing issues generically as well. Mix of hosts, great mix of topics (and they stay very on-topic for most shows). Much more consistent length-wise, around 45 min to an hour, as opposed to the rambling size of the HJRPG 'casts.
Fear The Boot: Not too dissimilar to HJRPG, listening to these guys is listening to a bunch of people hanging out. The GM knowledge is vast, and the advice is often solid, and comes from a good mix of rotating hosts, so you get good variety as well.

I've listened to others, but they've have either fallen by the wayside, or are just occasionally used.