In Deja Q, Worf's response is legendary, and Q's comeback here is cute, making the below exchange my favorite: "I have no powers. Q, the ordinary." "Q, the liar. Q, the misanthrope." "Q, the miserable. Q, the desperate. What must I do to convince you people?" "Die." "Oh, very clever, Worf. Eat any good books, lately?"
Another one of my favorites - and I'm going from memory, so I may not have it exactly: from "The Ultimate Computer": Spock (to Kirk): "Computers make excellent and efficient servants, but I have no desire to serve under them. A starship runs on many things, including loyalty to a man. One man. And nothing can ever replace it. Or him."
By memory, but you'll get the idea: "We found intelligent life everywhere in the galaxy, except the programming offices of NBC."
That's Kurt Vonnegut 'Welcome to the Monkey House' I believe. The Mirror Mirror quote according to chakoteya is 'It was far easier for you as civilised men to behave like barbarians, than it was for them to behave like civilised men.'
Pretty much every single line of "The Measure of a Man" is quotable, and a lot of it has indeed been quoted here. So I won't. Another favorite: "With the first link, the chain is forged. The first speech censured, the first thought forbidden, the first freedom denied, chains us all irrevocably" TNG - The Drumhead.
THERE.....ARE......FOUR.....LIGHTS ( capt Picard) Is my favorit but I also like Fate protects fools little children and a ship named enterprise ( will riker)
Jean-Luc Picard: Q, what is going on? Q: I told you. You're dead. This is the afterlife. And I'm God. Jean-Luc Picard: [ You are not God! Q: Blasphemy! You're lucky I don't cast you out or smite you or something. The bottom line is, your life ended about five minutes ago, under the inept ministrations of Dr. Beverly Crusher. Jean-Luc Picard: No... I am not dead. Because I refuse to believe that the afterlife is run by you. The universe is not so badly designed.
"Who is to say, that this history is any less proper than the other"? "I suppose I am". "NOT GOOD ENOUGH, DAMNIT, NOT GOOD ENOUGH!"
Many good ones in this thread! Riker (many times): "Rrrrrrred alert!" Data: "I just *love* scanning for life forms! [singing] Life forms! You tiny little life forms! You precious little life forms! Where are you?" (Especially loved Riker's reaction to this! )
Kirk in "Balance of Terror": "Leave any bigotry in your quarters. There's no room for it on the bridge."
"And you're all astronauts on some kind of a ... star trek..." "And I will make them pay for what they've done!"