Whenever I'm quoting Star Trek lines, the ones that come most easily to mind are from TUC. It had a lot of good ones IMHO. Not to say that the dialogue from any of the other movies was bad but there were a lot of good one-liners in TUC- moreso than the other movies, which seemed, on whole, to have less dialogue in general.
Chang: "In space, all warriors are cold warriors"
Kirk: "Still think we're finished?
McCoy: "More than ever!"
Kirk: "He was just about to tell us everything!"
Chekov: "You want to go back?"
McCoy: "Absolutely NOT!"
Spock: "Doctor, would you care to assist me in performing surgery on a torpedo?"
McCoy: "Sounds fascinating!"
McCoy: "I'd pay real money for him (Chang) to shut up!"
Kirk: "Well, once again, we've saved civilization as we know it."
McCoy: "And they're not going to be pressing charges."
Spock: "If I were human, I believe my response would be, go to hell! If I were human...."
Of course, the whole part about the bridge crew speaking Klingon-ese en route to Rura Penthe was hilarious!
I do like a lot of lines from TSFS though, particularly during the Enterprise theft scene.
Sulu: "Don't call me tiny!"
Uhura: "This isn't reality. This is fantasy! You wanted adventure, how's this? Feel the old adrenaline flowing? Now, get in the closet!
Styles: "Bridge, this the Captain. How can you have a yellow alert in Spacedock?"
and then, of course, there's:
Kirk: "Klingon bastards! You killed my son!"
Kirk: "Sorry about your crew but as we say on Earth, C'est LaVie!"
Kirk: "I........have had......enough....of....YOU!!!!"
Maltz: "Wait! You told me that you were going to kill me!"
Kirk: "I lied."
On second tought, maybe it's a toss up for me on these two.