... because it's kind of funny.
On last week's episode of Prison Break, I couldn't help noticing a long, random montage set to the theme music from House M.D.. Apparently some lazy music coordinator pulled the wrong track from the Fox music library. I would post this bizarre sequence, but due to random technical difficulties, I can't. Nevertheless, it got me thinking. What would happen if TV shows played the theme songs from other TV shows in the middle of an episode? The results are surprisingly entertaining.