Madonna (March 31, 1994)
In the spring of 1994, the Late Show was still clobbering Leno's Tonight Show in the ratings, and Letterman was in his rightful spot at the top of the cultural heap. So when Madonna came by the show in a willfully bratty mood, the host didn't even blink. Dropping f-bombs, offering Dave her panties and making lame sexual innuendos, the singer has rarely come across as crassly "provocative" as she did that night. (She later said that the show's writers egged her on to be as controversial and difficult as possible, in order to make the appearance memorable.) And he made every single second of it comic gold, refusing to be thrown by her stunts and working his slow-burn irritation to perfection. When she weakly tries to zing him on his hair — "Is that a rug?" — he fires back at her severe 'do, "What is that, a swim cap?" When she tries to extend her visit — "Can't this just go on and on?" — Letterman snorts, "It seems like it has, don't it?" Honestly, we would have watched a full hour of these two.