Well, we might as well put the forth the question to those who like Star Trek: what is your favorite episode?
As for me, my favorite episode would have to "All Good Things," the final episode of The Next Generation. That episode, for me, was simply representative of all things Star Trek, as well as being one of the single best endings to anything, ever. An honourable mention goes to "In the Pale Moonlight," my favorite Deep Space 9 episode.
*SPOILERS*
In the episode, the Federation is doing very badly in its war against the Dominion. Commander Benjamin Sisko is attempting to get the Romulans to join the Federation in the war, as they could be a decisive factor. Unfortunately, things are not going well in this attempt. Desperate, Sisko resorts to faking a recording, in the form of a data rod, of a Dominion meeting where the leaders of the Dominion discuss their plan to attack the Romulans. He gives the data rod to the Romulans, and all seems to be going well, until the Romulan commander confronts Sisko with what is probably the most famous line in all of DS9: "It'ssss a faaaaake!!", which of course has been immortalized in
this ytmnd, which will get extremely annoying if you leave it on for more than five seconds. All seems to be over for Sisko, as the Romulan ship departs, the commander furious. However, then comes the twist -- Sisko receives word that the Romulan ship has been destroyed by a bomb planted on board, and that the Romulans have recovered the data rod, which was not destroyed. Although I don't remember the exact details, the quality of the data rod which had made the Romulan commander realize its fraudulence could now easily be explained as a result of the explosion. As such, the Romulans take the rod as genuine and soon join the Federation in the war. Sisko soon discovers that the bomb was planted by Garak, a rather ambigious Cardassian resident of Deep Space 9 who has always been a fan favorite because of his myserious past, witty lines, and charming demeanor. Garak believed that the ends justified the means in this case, and went over Sisko's head in planting this bomb on the Romulan ship. Sisko is furious at Garak, but soon realizes that there is nothing he can do to change what has happened, and that he has, in fact, gotten what he wanted. The entire episode is in the form of a flashback as Sisko dictates his personal log. The episode ends with a chilling monologue by Sisko, possibly my favorite scene in Trek, and so good that I bring it to you
here. Of note, this is the only time in all of Star Trek in which a character directly addresses the camera. I love that scene, and I love this episode. It is such a poignant expression of the question "do the ends justify the means?" Simply a wonderful episode all around.
*END SPOILERS*
I don't feel like writing an analysis of "All Good Things" right now, but maybe I'll do that in the future. I also think I need to comment on "Darmok," another excellent episode of TNG.