His standup is very funny. His appearances on Letterman and Conan over the years are amazing. I actually shed a tear today. On a selfish level, I’m sad for all the laughs we are all missing out on. I think he would have done standup for another 30 years, like Rickles. Gone too soon.
He was your favorite comedian's favorite comedian. His relentless pursuit of amusement often trampled on social Norms (oops), and I think too many folks considered him an ass for it. Note that immediately at the beginning, the camera had to take Conan out of center shot to keep Norm out of frame. edit: OK, maybe sometimes he was kind of an ass. He didn't care. He seemed to do comedy mostly for himself. I dig that. Comedy is one of my central coping mechanisms. He was diagnosed with cancer nine years ago, three years before the 2015 Letterman appearance, but kept it almost completely to himself. I will miss him.