. >> reporter: not just danny mcbride. big names, judd apatow, steven wright, robin williams. >> he's a great guy. he's actually shy in a way. >> robin williams is shy? >> i think so. >> let's hear it for mr. marc mar maron! >> i've been doing stand-up comedy for more than half my life, is that it? i did my graduate work for chopping lines of cocaine for sam kinison. >> reporter: highs and lows he brings out interviews. >> it seems like you're part journalist, part therapist and part kindred spirit. >> yeah, i don't consider myself a therapist, but i've had to do that. >> reporter: in one accept society, he confronts carlos mancia on joke stealing. >> is there a chance you don't know you're doing that? >> with openers, possibly. >> and then you kind of went easy on ben stiller. i'm not interviewing war criminals here. >> reporter: at other times, he's more of a father confessor. norm macdonald told him about his struggles with gambling addiction. rainn wilson told him about his baha'i faith. in 1995, maron shared a magazin