We are now in violation of treaty.
Imperfection must be sterlized.
ITYM:
“There is no third planet now.”
“Don’t you think I know that? There was…there was. That thing…destroyed it…I heard them…four hundred of my men…calling for help…begging me…and I couldn’t…”
Best. Episode. Ever.
DAVID: Well, don’t have kittens. Genesis is going to work. They’ll remember you in one breath with Newton, Einstein, Surak.
CAROL: Thanks a lot. No respect from my offspring.
DAVID: Par for the course.
The remastered version is even better! Great sfx, much better than the original.
In play:
NO KILL I
This news really changes everything
I can’t believe how wrong I’ve been
Convinced myself we shared the same feelings
I won’t make that mistake again
No, the line was/is “There is no ‘third planet’!” Delivered with blunt finality.
Kirk always was a master of tact…
I believe it was “I have a ship to tend to,” echoing Harry Mudd.
'Twas Cyrano Jones, but I take your point.
Shut up, Stella!
You are, of course, correct. My mind must have been elsewhere. 
“Oh, yes. I know the place!”
More?
“I do not understand. I do not wish to see you harmed in any way.”
“Mister O’Brien says the weapon was in a state of discharge.”
“Perhaps something occurred during transport, Commander.”
“Have you ever won a case?”
“Winning isn’t everything!”
I demand it. I demand it!
"Linguistics background; you?"
“No, but it’s Uhura. Don’t ruin this for me. I will end your life.”
So her first name’s Nyota?
My… God! Shields. SHIELDS!
Lunkhead?!?
There was a young lady from Venus
Whose body was shaped like a…