Today marks 50 years since "Star Trek" debuted on TV. With a new film this summer and a new online show coming soon, the franchise is going strong. Here are 22 "Star Trek" episodes that helped create the legend.
"Where No Man Has Gone Before"
Anyone looking to get into "Trek" should start with the original series' second pilot, which NBC picked up after Lucille Ball urged the network to give the show another chance. In it, Kirk (William Shatner) is forced to decide between killing a power-corrupted Enterprise crew member or putting the ship at risk. It's an early example of the ethical dilemmas that would become part of the series' core.
"Balance of Terror"
This episode from the very first season introduces the Romulans, a war-like race that frequently locks horns with the Federation throughout the series. Spock leads the Enterprise into a battle against a brilliant Romulan commander in an episode that examines the nature of war and how people who find themselves enemies to each other can have more in common than it may first seem.
"The City On The Edge Of Forever"
One of the most heartbreaking episodes of the original series. A disruption in the time-space continuum requires Kirk, Spock and McCoy to travel to 1930s New York to stop the Federation from being erased from existence. The price Kirk must pay to save the future will haunt him forever.
"Mirror Mirror"
This is the episode that brought us Spock's famous bearded evil twin and a parallel universe where the Enterprise is an Imperial Starship run by a violent crew.
"Devil In The Dark"
Named by Shatner as his favorite episode, this story shows the crew trying to fight a subterranean creature killing members of a mining colony. Their plans get turned upside down when they realize the true motives behind the creature's actions.
"Galileo Seven"
Spock prides himself on being a logical man, but when he and several other Enterprise crew members get stranded on a planet, we get to see just what can get him to make impulsive decisions.
"Measure of a Man"
"Star Trek: The Next Generation" took a while to get out of the shadow of its predecessor, but when it did, it produced some TV classics. Here, Captain Picard (Patrick Stewart) is challenged to prove that his android lieutenant Data is a sentient being deserving of human rights, leading to one of the actor's finest speeches in his career.
"First Contact" (The Next Generation)
This episode takes the series back to the Federation's main goal: to seek out new civilizations. Picard makes first contact with an alien race about to develop intergalactic space travel. The varied reactions of the aliens provokes thought as to what we might do if people from another world gave humans an offer to expand to the stars.
"The Best of Both Worlds" (The Next Generation)
In a season finale cliffhanger, Picard is assimilated by the Borg, forcing Commander Riker to either try to save his captain or risk losing him in a fight to stop the Borg from reaching Earth. The stabbing orchestral score that plays at the end of the episode is spine-chilling.
"Chain of Command" (The Next Generation)
Another episode that has Picard in peril, but this time he can feel the pain. He is captured by the ruthless Cardassian race and put through unspeakable torture. Stewart shows Picard's anguish through physical contortions and hollow stares, and his admittance at the end that he was ready to break shows how torture can dehumanize and destroy even the most brilliant of human minds.
"The Inner Light" (The Next Generation)
Another Picard classic. In this episode, Picard ends up living an entire life as another man on a doomed planet. It is one of the most critically acclaimed "Trek" episodes ever, and is only one of three episodes from any series in the franchise to win a Hugo Award.
"Lower Decks" (The Next Generation)
In the original series, the rank-and-file of the Enterprise were often just used as cannon fodder that got killed off to show the danger of each episode's mission. "TNG" subverted that with this episode that showed the main cast from the perspective of their subordinates and how the Enterprise's risky missions affect everyone on board.
"Sarek" (The Next Generation)
Spock's father makes a special appearance on the Enterprise here, but it quickly turns bittersweet as it becomes apparent that he is undergoing Vulcan dementia. This profound episode explores the challenge of confronting one's mortality when the body and mind start to break down.
"All Good Things ..." (The Next Generation)
Many TV shows fail to provide a satisfying conclusion, but "The Next Generation" nailed it. The omnipotent Q challenges Picard to stop a time anomaly that threatens to destroy the human race, sending him into a puzzle that spans his entire timeline and may force him to sacrifice the Enterprise.
"In The Pale Moonlight"
"Star Trek: Deep Space Nine" subverted the utopian ideals of series creator Gene Roddenberry and casted a darker tone on the series. In this episode, Captain Sisko manipulates the Romulans into teaming up with the Federation against the evil Dominion. The sacrifice of his ideals for the greater good forces him to take a long hard look at himself.
"Far Beyond The Stars" (Deep Space Nine)
One of the most imaginative premises you'll see in any "Trek" episode. Sisko has visions of himself and his crew as the staff of a 1950s New York sci-fi magazine. His counterpart writes tales of Sisko's adventures aboard Deep Space Nine, only for them to be scrapped for featuring a black man as the captain and protagonist.
"Homefront" (Deep Space Nine)
The Patriot Act and Snowden leaks have made the "security vs. freedom" debate more heated than ever. Several years before that, "DS9" tackled the topic with a story in which shapeshifting members of the Dominion sow distrust within the Federation by disguising themselves within their ranks.
"The Siege of AR-558" (Deep Space Nine)
A major Dominion communications relay has been captured by the Federation, and now it's up to Sisko to help stop the Dominion from recapturing it. This episode is one of the finest examples of a sci-fi series demonstrating the true cost of war.
"It's Only A Paper Moon"(Deep Space Nine)
On "DS9," Nog is the first member of the greedy Ferengi race to join Starfleet. After losing his leg defending AR-558, he spends this episode struggling immensely to deal with PTSD, causing him to disappear into the virtual world to escape his pain.
"Death Wish"
"Voyager" is arguably the most maligned of the "Trek" series, but it had its own big contributions to the franchise. "Death Wish" explores the true cost of immortality when a member of the omnipotent Q Continuum named Quinn asks for his life to end.
"The Void" (Voyager)
Captain Janeway did many controversial things while in charge of the Voyager, but this is one of her best moments. The Voyager gets trapped in a pocket space where ships attack each other in a dog-eat-dog struggle to survive. It's up to Janeway to get them all to rally together to escape.
"Blink of an Eye" (Voyager)
The Voyager finds itself suspended over an alien civilzation, which evolves before their eyes in minutes. The Prime Directive of the Federation demands that Starfleet stay out of the affairs of civilizations not ready for space. What happens when a race builds their entire culture around them?
