A Sad Clown
My ideal Super Bowl halftime show would consist of absolute darkness and silence. In the center of the field would be a Clown, very sad, lit by a harsh spotlight. He would be standing on a nice stage.

Clown would be genuinely upset, and look rather morose and mopey. Clown would seem as though he had given up on life. He would shuffle around a small amount, but would primarily sigh and stare off into the blackness, tears slowly welling up in his already-bloodshot eyes.

This would go on for approximately seven minutes. Then, all of the lights would come on and Clown would walk silently off the field. Clown would be alone while he walked.

Then the rest of the game would be played and no one would speak of Clown.