To my mind, Deep Space Nine possesses the ideal balance for most ongoing serialized TV shows: Too little serialization and DS9 would lose its narrative advantages, and too much means risking a lot of “let’s stall for time” style entries that plague stuff like The Walking Dead. For my money, the only effective heavily serialized show on the air right now is Breaking Bad, which has the benefit of Vince Gilligan and his writing staff, and more importantly, a narrative that specifically lends itself to heavy serialization. Content should dictate structure, not the other way around, and too many shows these days see that serialization is the new thing and latch onto it as though the style in and of itself is justification enough. All of which is to say, the balance DS9 has achieved works pretty damn great.
(via an episode review at the AV Club, this summarizes PERFECTLY my problems with some modern TV shows, like the Walking Dead they mention.)