Some shows end when they come to a natural end, and that's a good thing. Shows that don't recognise when it's time to stop turn from masterpieces into objects of ridicule.
The Simpsons would be a good example of a show that should have ended years ago, before it turned from sheer genius into formulaic drivel. And Fawlty Towers is an example of the opposite, the writers refused to do any more series once they ran out of inspiration, so that the show would end of a high instead of fizzling away.
Some shows though get cut off mid-stream, and those are the ones that I think should come back. I think the cancellation that made me swear the loudest is that of Fire Fly, that was a show that was just getting started, had a massive amount of planned plot laid out, and was getting better and better with each episode! They did eventually make a film to finish off the plot, but it would have been much richer had they done it as a series.
All that is a long way of saying that I'm glad many of my very favourite shows had the good sense to end at the right time, but that I really wish FireFly had been let reach it's potential.
B.