Too many times I became vested in watching a show with the main story line having never been resolved and while one or two subplots would be resolved, two or 3 new ones would be unleashed...........then only to have the show cancelled after 1 or 2 seasons.
Now I wait to watch a show that has a continuing story line from week to week and season to season until I know that it is critically acclaimed and also has what the creator deemed as closure........
Sopranos
Breaking Bad
Lost