As we continue the celebration of Star Trek’s 50th anniversary, it’s only logical (pun intended) to countdown the top 10 episodes of the original Star Trek series. Strange as it sounds, it was both hard and easy to pick out the ten best episodes from the most phenomenal sci-fi TV series of all time. While the episodes listed in the three-part Top 50 countdown were classics in their own right, these particular ten stood out from the rest time and time again, and will probably continue to do long into the future. Most of these rankings may seem natural and obvious to many readers, but it’s just a testament to the strength and timelessness of these Star Trek episodes.

10. “Shore Leave” Captain James T. Kirk (William Shatner), commanding officer of the starship Enterprise, leads a landing party to an unusual planet where one’s private thoughts become reality. While this leads to many wish-fulfilling moments, such as Kirk’s reunion with a lost love, the planet’s nature creates dangerous situations like attacks from a medieval knight, a samurai and a fighter plane.

At times whimsical with a generous dose of the perilous “Shore Leave” was one of the more unique episodes of Star Trek and predated the ubiquitous holodeck shows of the spinoffs, but better done. Not only did the episode place our heroes in offbeat scenarios, but “Shore Leave” provided some curious insights of our heroes.

9. “The Corbomite Maneuver” This episode is a classic example of how a First Contact scenario might play out between human and alien and how it can potentially lead to disaster. In reality, this was the second Star Trek episode produced for the actual series and it shows. The production of Star Trek looked a bit different like the velour uniforms and Spock’s (Leonard Nimoy) harsher makeup.

Despite that, “The Corbomite Maneuver” is a standout classic because of the strength of its script. Upon encountering a mysterious alien presence Captain Kirk is forced to play a guessing game with the unknown alien who tests the Enterprise and its crew. Even though Kirk’s strategies are indeed impressive, what’s more unforgettable is the episode’s conclusion when the nature of the alien and its motive are revealed.

8. “The Trouble With The Tribbles” As one of the most popular episodes in any Star Trek, “The Trouble With The Tribbles” is also the funniest and for good reason. It’s still as much fun to watch today as it was 50 years ago (well, 49 to be exact, it first aired in 1967).

The Enterprise arrives at a Federation space station visited by belligerent Klingons feuding with the Federation over the claim of a nearby planet. As Kirk tries dealing diplomatically with the Klingons and the bureaucratic station heads, adding to his headaches is an infestation of furry animals called tribbles. Loveable at first, the balls of fur over-multiply and besiege the station and the Enterprise. The episode is famous for its many humorous moments, especially the iconic scene where Kirk is buried in a pile of multi-colored tribbles as he gets to the bottom of a mystery involving the station’s contaminated grain stores.

7. “Space Seed” Here’s the landmark episode that introduced Star Trek’s greatest villain, Khan Noonien Singh, played with great aplomb and gusto by Ricardo Montalban.

Khan and his cohorts were genetically enhanced superman/despots from the 20th century who were cryogenically frozen and revived by the Enterprise crew. Once thawed out, Khan’s ambitious nature drives him into an escalating battle of wits with Captain Kirk. This culminates in Khan with his allies seizing control of the Enterprise and capturing the ship’s crew. Of course, it’s up to Kirk to free his people and defeat the genetically superior despot.

Due to Montalban’s captivating performance, Khan clearly left a huge impact in Star Trek mythos and is why the villain was the clear standout in “Space Seed”. Kirk has faced many villains but Khan was his most dangerous and mesmerizing opponent. As we all know, Khan was so unforgettable that he had to return to Star Trek years later with the most popular Trek film Star Trek II: The Wrath of Khan.

6. “This Side of Paradise” What starts off as an intriguing mystery and quickly turns into a romance with an unlikely lead: Mr. Spock. “This Side of Paradise” opens with an Enterprise landing party investigating how colonists on a radiation-filled world are still alive. The answer soon comes in the form of symbiotic spores that infect the Enterprise crew.

The spores give the infected a feeling of unproductive bliss, including Spock who is now able to express his feelings with an unrequited love, Leila Kalomi (Jill Ireland) who he reunites with on the planet. Meanwhile the rest of the crew quickly abandon their duties and plan to spend the rest of their lives on the spore-infected world.

The focus on Spock and his newfound romance was an outstanding highlight thanks to Nimoy and Ireland’s excellent performances and a wonderful, romantic score. It was truly heartening to see Spock finally letting his hair down and experience a brief moment of happiness even though the plot’s conclusion was poignantly bittersweet.

5. “The Doomsday Machine” Forget about the Borg! The titular miles-long machine of destruction featured in this episode was a genuine galactic menace that can destroy planets.

The Enterprise finds the wrecked hulk of its sister ship, the Constellation, in the aftermath of a failed battle with the planet-killer machine that came from unknown regions. The sole survivor on the Constellation is Commodore Decker (William Windom check), a broken man haunted by the death of his crew due to the planet-killer.

As Kirk and Scotty (James Doohan) remain on the Constellation, Decker is transported to the Enterprise and soon assumes command of the ship. Driven by vengeance, he orders the ship and crew on a suicidal mission to destroy the indestructible planet-killer.

“The Doomsday Machine” is one of the original show’s most exciting entries thanks to its well written script and Windom’s absorbing performance as Decker. Although the futile efforts to attack the planet-killer left us on the edge of our couches, what was more riveting was Decker himself. Unable to deal with his past failures, Decker quickly proved to be more of a danger to the Enterprise crew than the planet-killer itself.

4. “The Naked Time” This was one of the earliest episodes to provide meaningful insights of the show’s beloved characters, even the supporting ones.

A landing party led by Spock inadvertently brings aboard the Enterprise a virus that spreads rapidly. Its effect is similar to alcohol or other drugs where the infected crewmembers’ inhibitions are loosened and they soon act out their innermost desires, demons and doubts.

 

Once Kirk and Spock contract the virus we gain a lot of knowledge about their personal feelings. Spock laments his cultural upbringing that prevents him from expressing feelings of love and friendship. Kirk bemoans the personal sacrifice he has made in his duty as a starship commander that doesn’t leave room for a  meaningful romantic relationship or true happiness. These revelations about them made them more endearingly relatable to viewers. But despite these setbacks, Kirk and his crew find a way past the illness to save the ship and win our eternal admiration.

3. “Balance of Terror” A true landmark episode not just for introducing Star Trek’s mainstay villains, the Romulans, but for its many subtextures related to Starfleet’s first encounter with the enemy race after a century-old war with them. On the surface, it’s easy to state that “Balance of Terror” is a thinly veiled remake of the World War II film The Enemy Below with Captain Kirk and the Enterprise playing a cat-and-mouse game with a Romulan Commander and his cloaked ship. But this episode offered so much more than a war story.

Helping this episode stand out was Mark Lenard’s sympathetic portrayal of the unnamed Romulan Commander whose presence established the Romulans as a more complex race. His Romulan was a weary and noble person who only wanted to complete his mission and getting his crew back home. Unfortunately that mission was attacking Federation outposts along the Neutral Zone.

Meanwhile, Kirk has to use all his skills to outmaneuver the crafty Romulan and prevent a war. Not only that he has to contend with newfound tensions and bigotry onboard his vessel with regards to Spock when it’s discovered that Romulans are offshoots of Vulcans. Buttressing these nuances was the fact that “Balance of Terror” was a gripping and suspenseful military yarn that left viewers feeling regret about the cruel fate that cast Kirk against the Romulan Commander since they shared many similarities.

2. “Mirror, Mirror” A transporter accident maroons Capt. Kirk, Dr. McCoy (DeForest Kelley), Scotty and Uhura (Nichelle Nichols) in  a parallel universe where their counterparts serve a barbaric Terran Empire instead of the benevolent Federation. Forced to assume the roles of their  doppelgangers, Kirk and his people have to stay one step ahead and blend into their new savage surroundings, while trying to find a way back to their reality.

At the time “Mirror, Mirror” aired, the notion of alternate realities and parallel universes was barely seen in live-action media. So seeing it done so well in Star Trek was a welcome novelty. From the moment we first see the alternate Spock sporting a goatee and the delicious overacting by the supporting actors as their evil counterparts, we were in for a treat.

As savage as this warped reality was, this particular episode is a lot of fun to watch, even though we recognize the dangerous plight of our heroes. This twisted version of the Federation with its amoral ways, such as climbing the military ladder via assassination, helped us to appreciate the more enlightened reality of the proper Star Trek universe. Thankfully, the showrunners behind the spinoff shows, Star Trek: Deep Space Nine and Star Trek: Enterprise were wise enough to re-visit this parallel universe.

1. “City on the Edge of Forever” Of course, this would be the best episode of the original Star Trek series, though there were many notable contenders. “City on the Edge of Forever” is best remembered for its behind-the-scenes machinations where the original script by Harlan Ellison was watered down to his dissatisfaction. Nevertheless, the episode is still not just the best Star Trek episode, but one of the best time travel tales ever.

Dr. McCoy is transported into Earth’s past and somehow alters history so that the Federation and Starfleet no longer exist. In order to correct history, Kirk and Spock voyage to the same past (1930s New York) to find their friend before he can change the timeline. While in New York, Kirk meets the love of his life, Edith Keeler (Joan Collins), an idealistic social worker who he finds inspiring. However, he soon learns she is to play a fatal role in history and it is solely up to him to decide the fate of future generations.

This episode works on so many levels, and not because it’s a terrific time-travel story. “City on the Edge of Forever” stands out from the other original Star Trek episodes due to distinctly mature tone, its poignant love story and of course, the heartbreaking, tragic conclusion where Kirk makes the harshest choice of his life. This episode deservedly won many acclaim, including the Hugo Award and the Writers Guild of America Award and its legacy is more profound. “City on the Edge of Forever” showed how Star Trek can expand past its trappings and tell genuinely profound stories that have stood the test of time.

José Soto