Late Night host David Letterman had already put on a suit covered in Alka-Seltzers and lowered himself into a vat of water. Really, how do you top that? On September 18, 1985, he debuted a future classic, the Top Ten List. (The surprisingly mundane topic? "Top Ten Words That Almost Rhyme with 'Peas.'") Working in late-night "was heaven in that the other people were so funny, and it was hell because you had to come up with new stuff all the time," then-head writer Steve O'Donnell, 71, tells Us. "That's why the Top Ten List was such a godsend: It was something you could do again and again.