When it debuted: 1982
Segment lowlight: This is one of those monotonous bits that is the same every time.

It seems that comedians never tire of piling on that oh-so-easy target of modern art. The gist of this bit is that Letterman guesses whether a piece was created by an ape or an artist. The gag was letter expanded to be called "Ape or Artist or Elephant?" Well, Dave, we may not know art, but we know what we like. Not this.