2. Bill Murray
Murray's legacy in Dave’s career is well established. He was the first guest on Dave's short-lived daytime show, the very first guest on Late Night and the first guest on Late Show. But the connection runs deeper than that. That surly reserve, that willingness to do the weird thing for a laugh: It's embedded in both men's DNA. For a couple generations of aspiring comics and procrastinating college students, Murray and Letterman's exchanges were like the meeting of too great smart-ass minds. Introducing Murray onto the show in 2013, Dave declared, "For my money, every film would be better if Bill was in it." And then, apropos of nothing (well, maybe that Soderbergh film Behind the Candelabra), Murray came onto the stage dressed like Liberace. "My heart has now taken flight," Letterman told him, clearly tickled. Ours too, Dave.