Often regarded as a bit darker than TOS or TNG, DS9 is a TNG spinoff that takes place aboard a space station and is the first Star Trek series to move from strictly episodic television into somewhat more seasonal story arcs, particularly towards the end. Commander Benjamin Sisko is not only a Star Fleet Officer, but the pilot episode establishes that he is also The Emissary and regarded as a religious figure by the population of the local planet. DS9 has more characters than most Star Trek series and deals with war, politics, religion and spycraft a little more seriously than TNG.
Star Trek Deep Space Nine
