My wife and I just finished watching through all seven seasons of Star Trek: Deep Space Nine. This series is, for my money, the absolute best of Star Trek. Granted, I've only watched through the first three Trek series (so far!), but any others would be hard pressed to top this one.
What makes this series so memorable are the shades of gray that it brings to the Trek universe. Both the original series and Next Generation feel to me like most westerns of the 1940s and 1950s: you always know who the bad guys are, and the good guys are always in the right. Deep Space Nine, on the other hand, feels like the grittier westerns of the late 1960s and 1970s: the good guys aren't always good, and the bad guys aren't always bad. There's such nuance in these stories!
Here are a few episodes that truly blew me away:
The Visitor
This season 4 episode will have you shedding a tear or two by the end. In this episode, an accident leaves Captain Benjamin Sisko frozen in time, leaving his son Jake with a lifelong obsession with rescuing his father, having his resolve tested when they briefly reunite every few decades. Wow!
Trials and Tribble-ations
The cast of the show are injected right into a classic Original Series episode, right alongside Captain Kirk and company! This was such a clever thing to do, and the execution was remarkable.
Far Beyond the Stars
Star Trek is at its best when it boils a plot down to the essence of science fiction. This episode literally delivers that exact premise: Captain Benjamin Sisko is worn down by the stress of the Dominion War. During a visit from his father, he experiences dream-like visions of being an African-American science-fiction writer facing racism in mid–20th century New York City. The main cast of the series, along with several recurring cast members, portray 20th-century humans in Sisko's vision; those who play alien characters appear in this episode unusually without their alien costumes and makeup. This might have been my favorite episode of the entire run.
In the Pale Moonlight
Captain Sisko shows just how dark he can be in this fantastic episode. The squeaky clean image of the Federation is shattered here, leaving us to ponder the evils beneath its outer veneer.
I highly recommend this series if you've never given it a chance.