Recently I said, that the hightpoint of the Terminator franchise is the TV series, and that was even on Network TV, not cable. If you look at HBO's output in this decade alone: Deadwood redefined the Western, Carnivale redefined Fantasy, Six Feet Under redefined family drama, etc.
TV shows for me also have more of a casual feel to them, not having to pay 100% attention the whole time.
This is what I don't get. If it isn't worth my full attention, then it isn't worth my attention at all. I despise shows designed for the "casual" viewer, e.g. by repeating their meager plot points after each commercial break for those who might have missed something.