Here's the penultimate installment of my 45 Best Treks Ever list:
15. All Good Things… (TNG)
Picard faces a riddle in the past, present and future. If he can't solve it, Q's dilemma will wipe humanity from existence. The conflict between Picard and his nemesis Q fills out a tremendous high concept sci-fi story. It's full of great character moments with the likes of Captain Beverly Picard, Professor Data, Governor Worf, and Admiral Riker. A fitting end to a great television series.
14. Yesterday's Enterprise (TNG)
The Enterprise-C is catapulted twenty years into a war-scarred future where Guinan must convince Picard to send it back, regardless of the cost. TNG's best time travel story sets an unusually dark tone, and manages to give Tasha Yar a much better death the second time around. The cast does a nice job portraying grimmer versions of themselves.
13. Journey to Babel (TOS)
A conspiracy endangers both Kirk and the Enterprise while carrying a group of diplomats that includes Spock's parents. Mark Lenard returns as Sarek, one of Trek's most enduring guest roles, and the combination of internal and external threats makes this episode great viewing. It also establishes lots of Trek background, including the Andorians, the Tellarites, and the Orions.
12. Relics (TNG)
The TNG crew finds Scotty in a trapped in a transporter beam, and he and LaForge must save the Enterprise from a Dyson's sphere. The best of Trek's crossover shows combines a great performance from James Doohan with an intriging sci-fi concept. The holodeck scene with Picard and Scotty discussing "old girlfriends" on the original Enterprise bridge is worth the price of admission all by itself.
11. City on the Edge of Forever (TOS) Kirk must let the woman he loves die in order to set the timeline right. Harlan Ellison's script won the Nebula award. Gene Roddenberry's re-write won the Hugo. "City" sets the bar for all time travel stories.
10. Far Beyond the Stars (DS9)
Sisko is given a vision of Benny Russell, a struggling African-American science fiction writer on Earth in the 1950's. DS9's ensemble delivers tremendous performances in a provocative story from Ira Behr. Seeing Rene Auberjonois, Armin Shimmermin, Mark Alamio, Jeff Combs, J.G. Hertzler, Casey Biggs and Aron Eisenberg perform without makeup made it even more special.
09. First Contact (TNG)
The Enterprise crew struggles to save Riker after he's injured and captured during an unusal first contact mission. TNG takes the clichéd first contact scenario and turns it on its head by putting our heroes in the alien role. It's a brilliant look at the actual mechanics of making contact with a new race, something rarely seen in the later Treks.
08. Best of Both Worlds, Part 2 (TNG)
After annhiliating a fleet sent to stop them, the Borg close in on Earth and the Enterprise races to intercept. The resolution to Trek's best cliffhanger falls a little short with its deus ex machina ending, but still boasts great scenes where Riker struggles to take Picard's mantle, and the Enterprise comes across the destroyed fleet at Wolf 359. The coda, where we realize Picard is still dealing with his assimilation, is superb.
07. The Doomsday Machine (TOS)
Kirk and his crew struggle to stop a planet-killing weapon from entering Federation space. William Windom gives an inspired performance as Commodore Decker, who's become suicidal after losing his crew to the planet killer. The hard sci-fi premise and real world analogy to nuclear weapons makes this episode still powerful today.
06. In the Pale Moonlight (DS9)
Sisko enlists Garak in a covert plan to bring the Romulan Empire into the Dominion War on the Federation's side at any cost. Avery Brooks is flawless in portraying an man so bent on achieving victory that he blinds himself to the immorality of the actions he condones. "Moonlight" is the quintessential DS9 episode, putting Trek's shining ideals to the test in the gray shades of the real world.