11 Best Episodes of "Star Trek: The Original Series"

If you've only seen the recent Star Trek movies, you might be eager to jump into the Star Trek universe. But the question is, where do you start? Any Trek fan would recommend watching the original series, but you might not be ready to binge watch all three seasons. Here are the eleven best episodes to start with.

11
of 11

"Arena" (Season 1, Episode 18)

Kirk fighting the Gorn captain
Kirk fighting the Gorn captain. NBC-Viacom

During a battle with unknown aliens, the powerful Metron transport Kirk and the alien captain to a planet to face trial by combat. Kirk and the Gorn captain are forced to match wits to save their ships. The fight between Kirk and the Gorn captain is so popular that Shatner recently reenacted it in a commercial.

10
of 11

"Balance of Terror" (Season 1, Episode 14)

Romulans aboard their warship
Romulans aboard their warship. NBC-Viacom

When the Enterprise encounters a mysterious alien vessel with the ability to "cloak" (turn invisible to all sensors), Kirk is forced into a cat-and-mouse game for survival. This signaled the first appearance of the Romulans in the Star Trek Universe. It shows Kirk's skill at strategy, and reveals the lost connections to the Vulcan race. The episode also works as a commentary on the racism that can spring up during times of war, which is still resonant today.

09
of 11

"Mirror, Mirror" (Season 2, Episode 4)

Kirk and the crew in the Mirror Universe
Kirk and the crew in the Mirror Universe. Paramount Television

During a teleporter malfunction, Kirk and his companions end up in an alternate reality where the Enterprise is a warship under the command of a cruel and sadistic empire. This episode introduced the Mirror Universe, a place where the heroes are the villains and the villains are the heroes. Later series such as Deep Space Nine and Enterprise revisited and expanded on the concept.

08
of 11

"Space Seed" (Season 1, Episode 22)

Kirk and Khan on
Kirk and Khan on "Space Seed". Paramount Television

When the Enterprise discovers a marooned spaceship, they accidentally release a group of genetically engineered supermen, led by the brilliant and powerful Khan Noonian Singh. Khan seizes control of the Enterprise, and threatens to launch a new war. This episode introduced Khan, who later became the main villain in Star Trek II: The Wrath of Khan. To understand Wrath of Khan and Into Darkness, you'll need to see this episode

07
of 11

"The Doomsday Machine" (Season 1, Episode 6)

USS Constellation approaches the planet killer
USS Constellation approaches the planet killer. Paramount Television

When a planet devouring machine heads for populated space, the Enterprise must find a way to stop it before it destroys populated space. But another second captain whose ship was destroyed by the machine seizes command of the Enterprise in pursuit of revenge. The captain's obsession with the planet killer is a classic adaptation of Moby Dick.

06
of 11

"The Devil in the Dark" (Season 1, Episode 25)

Spock examines the horta
Spock (Leonard Nimoy) examines the horta. Paramount Television

When the Enterprise investigates attacks on a mining colony, they discover a rock-based creature known as a horta. The horta starts out as an enemy, but they soon discover a horrifying secret behind its rampage. The episode is famous for its exploration of the definition of life, and the scene where Spock performs a mind-meld with the creature is a classic.

05
of 11

"The Trouble With Tribbles" (Season 2, Episode 15)

Kirk buried in tribbles
Kirk (William Shatner) buried in tribbles. Paramount Television

When Uhura brings aboard a cute alien known as a tribble, the creature multiplies uncontrollably. At the same time, the Enterprise faces off against Klingons while trying to protect a shipment of grain. The humor in this episode is unparalleled, and the cuddly tribbles became one of the most beloved aliens in the Star Trek universe. The episode became the center of a later episode on Deep Space Nine.

04
of 11

"Squire of Gothos" (Season 1, Episode 17)

Colonel Trelane in
Colonel Trelane in "Squire of Gothos". Paramount Television

When the crew lands on a mysterious planet, they encounter Trelane, a mysterious being with limitless powers. Trelane alters the crew and the Enterprise for his twisted amusement. The idea of the omnipotent being toying with humanity later became an ongoing theme with Trek, especially with in The Next Generation with Q.

03
of 11

"The Naked Time" (Season 1, Episode 4)

Sulu confronts the bridge
Sulu (George Takei) confronts the bridge. Paramount Television

When the Enterprise crew is infected with a strange liquid, their inhibitions are unleashed. The infection threatens to destroy the ship as the crazed crew members tamper with the engines. This episode allowed the characters to masterfully play against type with Sulu showing his fencing skills, and Spock struggles to contain his emotions.

02
of 11

"City on the Edge of Forever" (Season 1, Episode 28)

Kirk and Spock face the Guardian of Forever
Kirk and Spock face the Guardian of Forever. Paramount Television

When Doctor McCoy jumps through a time portal known as "The Guardian of Forever," Kirk and Spock must jump in after him to 1930's Earth. But when Kirk discovers the woman he loves must die to save the future, he grapples with the moral implications. This is one of the most emotional and famous episodes of Star Trek history.

01
of 11

"Amok Time" (Season 2, Episode 1)

Kirk and Spock fight in
Kirk and Spock fight in "Amok Time". Paramount Television

When Spock begins acting strangely, the crew discovers he is undergoing a hormonal change known as "pon farr." The only way to cure him is to return to his home planet Vulcan to mate or fight. The fight between Spock and Kirk is one of the most memorable in Trek history. Pon farr has been referenced in later movies such as Star Trek III: The Search for Spock and TV shows such as Star Trek: Voyager.

Closing Thoughts

This is by no means an exhaustive or definitive list, and other fans may argue the ranking or include other episodes. Watch them yourself, and go on to enjoy the entire run!