The 10 Best 'Star Trek' Episodes Ever

Best 'Star Trek' Episodes

With five live-action TV series, each ranging from three to seven seasons, there's been a ton of great "Star Trek" over the years.

Here are 10 episodes — two from each live-action series — that we rank as the best. In each of these episodes, you're guaranteed to learn something about the "Star Trek" universe and, in some cases, even challenge your own moral beliefs about right and wrong.

10. "Regeneration," 2003 ("Star Trek: Enterprise")

The Borg's terrifying powers of assimilation are tough enough to face when you're in a starship with weapons on board. But what about if they were discovered on your own planet? "Regeneration" shows what happens when Borg are found above the Arctic Circle on Earth, facing a fairly unprepared group of people — remember, "Enterprise" is a prequel series and takes place just as starship travel begins. The creative methods "Enterprise" used in fighting the Borg are fun to watch.

9. "Equinox," 1999 ("Star Trek: Voyager")

As fans of the series know, the premise of "Voyager" is that the crew becomes stranded some 75 years' travel away from home. By Season 6, we are pretty confident that the crew has well assimilated (so to speak) this knowledge, but they come across a ship in the same quadrant that has more questionable methods in dealing with the problem.

We see the stranded ship engage in subterfuge in this two-parter during the Season 6 finale and Season 7 premiere, which reminds us of how badly "Voyager" could have gone with a different crew. While "Star Trek" only touched on this theme briefly in "Voyager," mutiny by crews is also explored a few times in the series "Battlestar Galactica" in the 2000s.

8. "Borderland" / "Cold Station 12'' / "The Augments," 2004 ("Star Trek: Enterprise")

This incredible trio of episodes has some throwbacks to "Star Trek: The Next Generation" — mentions of Dr. Arik Soong, the grandfather of Data's creator, for instance — as well as the original "Star Trek," with some oblique references to the noted villain Khan. While these episodes came too late in the run of "Enterprise" to save the series from cancellation, they did show some creative flair with "Star Trek" lore, with the addition of references to genetic engineering, a hot topic in the current affairs of the time.

7. "Emissary," 1993 ("Star Trek: Deep Space Nine")

Pilots of "Star Trek" series are often unbearable to watch, but this one is an interesting exception. Viewers saw an interesting puzzle early in the two-part episode. The beloved Capt. Jean-Luc Picard of "The Next Generation" is portrayed as an enemy to Benjamin Sisko, the man considering taking the position of commander on "Deep Space Nine"; the conflict stemmed from a Borg attack and the death of Sisko's wife. There's nothing better than starting a new series with a moral quandary for fans to argue about. ['Star Trek' Stars Celebrate 50 Years of Hope at Comic-Con]

6. "Living Witness," 1998 ("Star Trek: Voyager")

Writing history is never a neutral process, as there are so many viewpoints to consider. At times, countries must come to grips with the mistakes of their past that their ancestors may have actually believed were victories.

In "Living Witness," the holographic doctor of "Voyager" is reactivated about 700 years after the series' events take place. He sees a museum exhibit that talks about the "warship Voyager" and some things the starship did that this museum portrays as extremely negative; the doctor then spends most of the episode trying to set the record straight, as he was there at the time.

5. "In the Pale Moonlight," 1998 ("Star Trek: Deep Space Nine")

Here, an Enterprise crewmember turns bad — but for the greater good. Commander Benjamin Sisko decides that he needs to bring the Romulans, a noted enemy of the Federation, onto the Federation's side to win a greater war. Immediately, the unprepared Sisko is thrown into a situation where he needs to ally with a Cardassian spy, a former prison convict and other unsavory characters to get the job done.

We'll let you watch the episode to find out the conclusion, but let it be known that Sisko does break a few rules in his quest — and that he still thinks it's the best choice, even though he has some moral qualms about it.

4. "The Best of Both Worlds," 1990 ("Star Trek: The Next Generation")

The Borg — a race that assimilates everything that comes into its way into a vast collective — make an unexpected invasion of an area that is supposed to be reserved for the United Federation of Planets, which the USS Enterprise represents.

Through a series of complicated events, the starship comes face-to-face with the Borg, and Picard is captured, ultimately becoming assimilated by the aliens. This season ended on a cliffhanger, with Picard — calling himself "Locutus of Borg" — ordering the USS Enterprise to surrender and assimilate. The cliffhanger, considered a huge shocker at the time, set up several other Borg-related episodes as well as the movie "Star Trek: First Contact" (1996). [The Evolution of 'Star Trek' (Infographic)]

3. "The Menagerie," 1966 ("Star Trek: The Original Series")

This two-part episode plays on our expectations of Spock, a logical Vulcan alien who usually runs things exactly by the book. In an uncharacteristic maneuver, the Vulcan kidnaps his former commander, Christopher Pike. He sets the Enterprise on course to Talos IV — a planet that Spock well knows is off-limits for Federation officers — and then Spock voluntarily assents to a court martial to talk about why.

"The Menagerie" is noteworthy not only for playing with our expectations of reality but also for a creative use of old footage. A large part of the episode reruns parts of "The Cage," the original pilot for "Star Trek." That pilot was ultimately scrapped, and the series launched with an almost entirely rebooted set of main characters. [What I Learned by Watching Every 'Star Trek' Show and Movie]

2. "The Trouble with Tribbles," 1967 ("Star Trek: The Original Series")

Tribbles are an adorable species — fuzzy, small, almost like a spherical teddy bear — that have an unfortunate ability to reproduce. After the crew receives a single Tribble, generations of Tribbles quickly begin to take over the USS Enterprise, soon crowding the crewmembers out of their own quarters. Before long, the Tribbles start getting into the food stores and consuming anything edible on the Enterprise.

The ultimate solution to the problem is creative. And don't worry — you don't see anything bad happen to these cuties. In the meantime, you can enjoy the hilarity, including a wonderful scene where a shower of Tribbles drops onto Capt. James T. Kirk's head.

1. "The Measure of a Man," 1989 ("Star Trek: The Next Generation")

"Star Trek" turns its attention to the android Data in a heartbreaking episode about how easily human rights can be disregarded for those who are a bit different. Data, we are informed, is going to be disassembled so that Cmdr. Maddox (a Starfleet cyberneticist) can study him. Data, naturally, is not pleased with this prospect and would like to resign, but he's told he can't because Starfleet considers him property.

This sets the stage for a riveting legal drama, where Capt. Jean-Luc Picard represents Data's interests and Cmdr. William Riker is pressed into reluctantly representing Maddox's side.