Mine is with Jeff Evans (#977) who was a rescue climber on Mt. Everest.
What are yours? I've just recently started listening to him and they're great.
On a real note: I enjoy that Joe is allowing politicians (Andrew Yang, Bernie Sanders, Dan Crenshaw etc.) to be on the show to discuss policy issues at length. I'm hoping in the future that we'll get away from the sound bite-esk types of debates that the Networks currently hosts.