People talk all the time about how shows are stretched out past their expiration date, lasting longer than they should, and tarnishing the memory of earlier, great seasons. Be it the Simpsons, the Office, 30 Rock, or House, very few TV shows go on for more than 6 seasons without resolving their original arcs, and just spend the rest of their time treading old ground and jumping over sharks. The only shows people ever seem to complain about the cancellation of are those that only last a couple seasons (Arrested Development, Freaks and Geeks, Firefly, Pushing Daisies).
However, are there any shows you feel break this rule? Is there a TV show that lasted more than say, 100 episodes that you still wish you had more of?
The only examples I can think of are 24 and Seinfeld. While both ended not nearly as strong as they began (or in Seinfeld's case, the third season began), they were still fantastic shows with seemingly endless pools for episodes.