While I think all five Star Trek series are excellent, DS9 stands out just that little bit extra. The stories of Deep Space Nine are much more complex and you really have to watch most episodes in the correct order to fully appreciate the series. The characters are also more complex and the depth of the character development is incredible. This even includes many of the guest characters such as Garak, Dukat, Vedek/Kai Winn, Vedek Bariel, Weyoon, Damar and even Morn! With many of the characters, you never quite know which side they are on or what sort of secret agenda's they are hiding. In one episode you think a character is a "good guy", but then several episodes later, he/she can change.
In general, DS9 is darker and grittier than the other Star Trek series. While it does have the Star Trek idealism and optimism, the series deals with war, military occupations, terrorism and espionage. It also has slightly more sexual references (although it is mostly implied, not shown). Overall, DS9 is not quite as much of a "family show" as the others but I think this has given the production staff more creative freedom to explore certain themes that wouldn't be possible in the other Star Trek series. If you like the other Star Trek series, but you want a bit more depth and complexity, I highly recommend DS9.
BTW, the season 4 premiere ("The Way of the Warrior") is probably a good place to start watching the show if you can't be bothered watching the full seven seasons. This is where the show really kicks off. While the first three seasons are good, they don't quite have the story arcs and big events that the later seasons feature.
In general, DS9 is darker and grittier than the other Star Trek series. While it does have the Star Trek idealism and optimism, the series deals with war, military occupations, terrorism and espionage. It also has slightly more sexual references (although it is mostly implied, not shown). Overall, DS9 is not quite as much of a "family show" as the others but I think this has given the production staff more creative freedom to explore certain themes that wouldn't be possible in the other Star Trek series. If you like the other Star Trek series, but you want a bit more depth and complexity, I highly recommend DS9.
BTW, the season 4 premiere ("The Way of the Warrior") is probably a good place to start watching the show if you can't be bothered watching the full seven seasons. This is where the show really kicks off. While the first three seasons are good, they don't quite have the story arcs and big events that the later seasons feature.