re: How long should a TV Show Run

6 to 7 is probably a good run

If the writing can sustain it, maybe 10, but those will be outliers. Some great shows run out of gas at about 50 or 60 episodes and limp along. The mark of a great show is a 6 or 7 year run and they know when to walk away leaving you wanting a little more - about the closest to perfect timing for me, again, is The Shield - despite the fact they had to basically add about 8 episodes when expanding the final season to 2 shortened final seasons, there were really no more stories to tell when they wrapped, but I didn't fell like they hung around too long.

I'm curious to see how they finish up Breaking Bad, because that will be a candidate as well.