Depends what you're interested in, really. For just generally interesting conversations, any of the Neil Degrasse Tyson ones, Louis Theroux, Bill Burr, Henry Rollins and there's an old Anthony Bourdain one. Other than that, just pick a few names you recognise or are interested in and start watching. A lot of the comedian ones can get a bit shit because it just becomes them comparing notes about clubs they've played and people they know. He also went through a phase where he had a lot of hunters and shit on and that was mind-numbingly boring. For the most part though, a lot of the scientists and experts he gets on are at least interesting.
The Jesse Ventura one was interesting. He's done 4 or 5 with Bill Burr and they're all great, he did one with a woman who left the Westboro Baptist Church and one with Leah Remini who left Scientology. Worth listening to if either those particular cults interest you, and of course I'm a prominent member of both.
oh this one was excellent