Every episode, every week since they started. The game bears no serious resemblance to my own games, outside of the fact they're playing D&D, as we don't roleplay as much or to the extent the they do on the show, but all the same I've been hooked since the start.
The characters are engaging, as are the story arcs, and the people are genuinely great to just "watch". And I mean, wtf else am I going to do with that time? If I can't scrounge up four hours in a week, even with work, family, etc., then I have other problems to address.
I'll also watch most of their other content, though with far less consistency, except for Talks Machina and Between the Sheets which I've also come to enjoy.
It won't be for everyone, but its not trying to be. It's a more enjoyable way to spend four or so hours out of my week than watching most of the other crap that's on TV or streaming apps these days, unless I wanna watch IT Crowd, Always Sunny in Philadelphia or some of my other favorite series for the millionth time.