Many fans claim that introduction of Guinan (Whoopi Goldberg) and the Borg, TNG season 2 brings some great additions to the Star Trek universe that continue to affect the franchise today.

Unfortunately, Star Trek: The Next Generation season 2 begins with a whimper with the lackluster "The Child," a leftover script that found its way into the show thanks to the 1988 Writers Guild of America Strike. (The Writers Strike also led to the abysmal season finale, "Shades of Gray," and the less said about that episode, the better.) Still, as the season progressed, TNG began turning into the great sci-fi show it would eventually become. TNG season 2 offers some standout moments for the regular cast, especially Captain Picard and Lt. Commander Data (Brent Spiner), with the best episodes at the top of the ranking.

10 "The Royale"

Star Trek: The Next Generation Season 2, Episode 12

When the Enterprise finds debris from an old Earth ship orbiting an uninhabitable planet, Commander William Riker (Jonathan Frakes), Lt. Commander Data, and Lt. Worf (Michael Dorn) beam down to investigate. Once there, they encounter an incongruous revolving door surrounded by a black abyss. The door leads to an old Earth hotel and casino that the away team eventually learns comes straight from the pages of a book.

Nearly 300 years before, a group of unknown aliens had found a lone Earth astronaut and built a reality for him based on a bad pulp novel in his possession. As the away team plays out the events of the book, Data goes on a winning streak at the craps table in one of the episode's best moments. TNG's "The Royale" may not provide a profound exploration of humanity, but sometimes it's enough for Star Trek to simply be fun.

9 "Time Squared"

Star Trek: The Next Generation Season 2, Episode 13

In "Time Squared," the Enterprise encounters a drifting shuttlepod containing a duplicate of Captain Picard from six hours into the future. The original Picard is disturbed by the idea that he abandoned the Enterprise and tries to question his future self to no avail. The Enterprise soon gets trapped within a vortex and Picard reasons that he left to draw the attention of the alien being controlling the vortex.

Picard's double then awakens and tries to leave aboard the shuttle, but the original Picard kills his doppelganger. The Enterprise then flies straight into the vortex and emerges safely on the other side, after which the second shuttle and second Picard disappear. Although not everything about "Time Squared" makes sense, it provides a fun and compelling mystery that unsettles even the unflappable Picard.

8 "The Schizoid Man"

Star Trek: The Next Generation Season 2, Episode 6

When the Enterprise travels to provide medical care to Dr. Ira Graves (W. Morgan Sheppard), the reclusive scientist tries to achieve immortality by transferring his consciousness into Data. Graves claims that he taught Data's creator, Dr. Noonian Soong, everything he knew, effectively making him Data's "grandpa." When Data returns to the Enterprise after Graves' supposed death, the crew soon notice the android's strange behavior.

"The Schizoid Man" marks the only appearance of Vulcan physician Dr. Selar (Suzie Plakson), though Suzie Plakson would return a few episodes later as Klingon emissary K'Ehleyr.

After Graves accidentally harms his young assistant Kareen (Barbara Alyn Woods), he transfers his knowledge into the Enterprise computer systems and allows himself to die. "The Schizoid Man" is not perfect, but strong performances from Brent Spiner and W. Morgan Sheppard help elevate the story. Plus, the episode has several genuinely funny moments, particularly Data's beard in the cold open and his delivery of Graves' eulogy.

7 "Pen Pals"

Star Trek: The Next Generation Season 2, Episode 15

In this underrated Star Trek: The Next Generation episode, Data befriends a young girl named Sarjenka (Nikki Cox), whose planet is on the verge of destruction. Data brings this information to Captain Picard, but he is hesitant to intervene because of Starfleet's Prime Directive. However, Picard soon finds that he cannot ignore Sarjenka's pleas for help.

The Enterprise is able to restore the planet's geological system, but Data has to temporarily bring Sarjenka aboard the Enterprise, much to Picard's frustration. In the end, Dr. Katherine Pulaski (Diana Muldaur) erases Sarjenka's memories, but the encounter remains something Data will never forget. "Pen Pals" is an incredibly sweet episode that presents one of the earliest clues that Data feels more than he would ever it.

6 "Peak Performance"

Star Trek: The Next Generation Season 2, Episode 21

As the Enterprise takes part in combat exercises, a Zakdorn strategist named Sirna Kolrami (Roy Brocksmith) comes aboard to mediate. Picard takes command of the Enterprise, while Riker is given the USS Hathaway. Believing the wargames to be a real battle, a Ferengi marauder approaches, but the Enterprise and Hathaway work together to scare the Ferengi away.

Data's loss of confidence leads to an iconic and useful piece of advice from Picard: "It is possible to commit no mistakes and still lose. That is not a weakness; that is life."

Meanwhile, Kolrami beats Data at the game Strategema, causing the android to question whether his programming is malfunctioning. In a rematch, Data ends the game in a stalemate, much to Kolrami's frustration. Every major character gets their moment in "Peak Performance," and the episode keeps things interesting with a fast-paced main storyline and a solid B-story.

5 "The Emissary"

Star Trek: The Next Generation Season 2, Episode 20

When Klingon emissary K'Ehleyr (Suzie Plakson) comes aboard the Enterprise on a diplomatic mission, she and Worf rekindle their romance. K'Ehleyr has been sent to help the Enterprise make with a Klingon battlecruiser whose crew has been in suspended animation for over 75 years. These Klingons believe they are still at war with the Federation, and K'Ehleyr works with the Enterprise crew to find a way to convince them to stand down.

K'Ehleyr returns in TNG season 4, episode 7, "Reunion," with Worf's young son Alexander (Jon Paul Steuer), who was conceived during "Emissary."

Worf wishes to marry K'Ehleyr, but she refuses as she does not follow strict Klingon traditions. Worf and K'Ehleyr work together to convince the Klingons that the war is over, and they part on friendly . Suzie Plakson is simply magnificent as K'Ehleyr, and she plays wonderfully against Michael Dorn's Worf. The storyline of the episode is solid enough, but really it's K'Ehleyr and Worf who steal the show.

4 "Elementary, Dear Data"

Star Trek: The Next Generation Season 2, Episode 3

"Elementary Dear, Data" follows Data and Geordi as they embark on a holodeck adventure as Sherlock Holmes and Dr. Watson. When Geordi asks the Enterprise computer to create an adversary capable of defeating Data, the ship grants Holmes villain Professor Moriarty (Daniel Davis) awareness of his status as a hologram. Moriarty evolves beyond his programming, gaining access to the ship's controls and requesting to leave the holodeck.

Captain Picard informs Moriarty that they do not have the technology for him to exist outside of the holodeck, but agrees to save his program and keep researching solutions. With its unique story and compelling villain, "Elementary Dear, Data" remains one of Star Trek's best holodeck stories. Plus, it's great to see Data (and Brent Spiner) have some fun as Sherlock Holmes, and Moriarty is an incredibly compelling and sympathetic villain.

3 "A Matter Of Honor"

Star Trek: The Next Generation Season 2, Episode 8

When the Enterprise participates in an officer exchange program, Commander Riker volunteers to temporarily the crew of the Klingon ship IKS Pagh. Riker whole-heartedly embraces his new role on the Klingon vessel, quickly earning the respect of his Klingon crewmates. When the Klingons find a strange lifeform eating away at their ship's hull, they believe it to be some kind of new Federation weapon.

The Klingon Captain Kargan (Christopher Collins) prepares to attack the Enterprise, despite Riker's attempts to convince him otherwise. Riker eventually takes control of the Pagh, and the Enterprise helps remove the organism from the Klingon ship's hull. Not only is "A Matter of Honor" a great episode for Riker, as he adapts to his new situation while remaining loyal to Starfleet, but it also offers fascinating insight into life aboard a Klingon ship.

2 "Q Who"

Star Trek: The Next Generation Season 2, Episode 16

John de Lancie's Q returns for his third visit to the Enterprise-D in "Q Who," in which he flings the ship thousands of light years across the galaxy. Q claims that Captain Picard and his crew have become too arrogant, and that they are not prepared for all the "wonders" and "terrors" of the vast universe. To show them what's out there, Q brings the Enterprise face-to-face with the Borg.

"Q Who" teases a complicated history between Q and Guinan, but Star Trek has yet to fully explore this relationship.

Diplomacy has always been one of Picard's greatest strengths, but he cannot reason with the Borg. After the Borg kill eighteen crew and remain resistant to Picard's attacks, the Enterprise captain asks Q for help and the omnipotent being returns the ship to its original location. "Q Who" is not only one of Q's best Star Trek episodes, but also serves as an excellent introduction for the Borg, who come across as genuinely frightening.

1 "The Measure Of A Man"

Star Trek: The Next Generation Season 2, Episode 9

When cyberneticist Dr. Bruce Maddox (Brian Brophy) visits the Enterprise-D, he declares his intentions to dismantle Data for further study. Data, of course, opposes this course of action, but Maddox claims the android to be the property of Starfleet. This leads to a powerful trial in which Captain Picard points out what a dangerous precedent it would set to declare Data property, essentially laying the groundwork for a slave race.

From Data's earnestness to Captain Picard's powerful speech to Riker's damning defense, "The Measure of a Man" delivers a near-perfect episode of television with a quintessentially Star Trek message. The episode also marks an important step on Data's personal journey, and a court decision that reverberates throughout the Star Trek universe. "The Measure of a Man" is not simply the best episode of Star Trek: The Next Generation season 2, but arguably the best episode of the entire series.