Pre-Ass-Kicking One-Liner/Live-Action TV

"Buffy: If I was at full Slayer power, I'd be punning right about now."
 * Subversion: the Buffy the Vampire Slayer episode "Helpless" had Buffy Brought Down to Normal for the duration, which also neutered her ability to deliver a suitable line when she finally managed to defeat the bad guy:

"Buffy: I'm Buffy, the Vampire Slayer. And you are?."
 * In the episode "Anne", Buffy has run away from home and changed her name to Anne (her middle name). In the course of the episode, she finds herself trapped in a demonic dimension where humans are made into slave labor. One of the demons is trying to break the humans' spirit by asking them "Who are you" and hitting them if they answer anything but "No one". What does Buffy answers, just before kicking everyone's ass?

"Angel (in vamp face): Can you pick out the one word there you probably shouldn't have said?"
 * When Buffy is gone, Willow tries to replicate her punning—doing it herself between Seasons 2 and 3 (when Buffy was in L.A.), and programming it into the Buffybot between Seasons 5 and 6 (when Buffy was dead). With minimal success: "That'll put marzipan on your pie plate, bingo!"
 * Dark/Royally Pissed Off Willow is actually quite adept at badass one-liners. Standouts include I. OWE. YOU. PAIN. and "Bag of tricks?" "Bag of knives ".
 * Which brings us to the most cold-blooded pre-killing line of all time: "Bored now." Which was made more poignant by the fact that it was Vampire Willow's catchphrase, last heard 3 years before.
 * Angel attempted a ton of these. One of the few that stuck was in the series finale. Angel is being tossed around humiliatingly by one of the chief mooks, who takes time to gloat over this, explaining that Angel cannot defeat him, that the power of The Big Bad . Cut to Angel switching to vamp face.

"Max: What did I say would happen if I caught you peeping again? Guy: Can't help it Max, you're the bomb. Max: Kaboom. (Max delivers a Groin Attack.)"
 * Dark Angel: When Max catches a Peeping Tom.

"Gene: Today, my friend, your diary entry will read "Took a prozzie hostage and was shot by three armed bastards.""
 * Doctor Who: "EXTERMINATE!"
 * "Who are you calling small?"
 * "This is a FIGHTING hand!"
 * "I'm quite spry for my age..."
 * "You're a bad dog." "Affirmative."
 * "I'm River Song. Check your records again."
 * "I'VE GOT A SAYING, FEEL THIS!"
 * "Would you like me to repeat the question?" (more post-asskicking, but still awesome.) Before that moment, there was this. " Where. Is. My. Wife. " By the same guy: "Heil!"
 * Gene Hunt of Life On Mars 2006 and Ashes to Ashes is especially fond of these—among the most memorable being his first line in the latter series:

"Gene: *Generic prostitution insult* Alex: *SLAP* Gene: Better now? Alex: No. *Punches him in the jaw* Better now. Come on ladies, let's get pissed."
 * Which was based on his original, fondly remembered "You are surrounded by armed BASTARDS!" Gene get's a ton of these.
 * Alex also gets a pre/post one-liner in the first series;

"Cutter: Enough. *proceeds to shoot Future Predator*"
 * On Community, during the second paintball game, a third City College stormtrooper runs up to the two celebrating that they've won. It's actually Pierce in disguise, and when asked who he is, his only reply is "Your mother's lover!" before opening fire and winning the game.
 * In the first Paintball game they take down the chess club with "Checkmate, bitches!"
 * Possibly the most emphatic of all. In the finale of the second series of Primeval, after Cutter is being played with by a Future Predator:

"Cutter: *when faced with giant mer creature* Time to go home."
 * Cutter gets a lot of these.

"Merlin: *Gets up from normally deadly injury* You should not have killed my friend. *And then proceeds to harness lightning by merely lifting his hand (in the Merlinverse, powerful magic requires incantation)*"
 * At the end of the first series of Merlin, this gem.

"Guinan: (fires a blast into the air) This is a little souvenir I picked up from Magus III. That was setting number one. Anyone wanna see setting number two?"
 * An episode of Star Trek: The Next Generation had Whoopi Goldberg's bartender character breaking up a bar fight with a big gun:

"Janeway: (to a blustering Kazon captain) You know, I'm an easy person to get along with most of the time. But I don't like threats, and I don't like bullies, and I don't like YOU."
 * Meanwhile, on Star Trek: Voyager, Janeway has a couple, such as "Time's up!" and "Time to take out the garbage." (It makes sense in context.)

"Jem'Hadar First: (to his Mooks) I am First Omet'iklan, and I am dead. As of this moment, we are all dead. We go into battle to reclaim our lives. This we do gladly, for we are Jem'Hadar. Remember: Victory is Life! Chief O'Brien: (to his Redshirts) I am Chief Miles Edward O'Brien. I am very much alive, and I intend to stay that way."
 * "Hello. I'm Captain Kathryn Janeway. Welcome to the bridge." immediately before the self-destruct detonated and blew up a parallel universe duplicate of Voyager
 * Star Trek: Deep Space Nine. Both used and spoofed in the episode "To the Death", where the crew of the Defiant team up with the Jem'Hadar to track down some renegades.

"Eliot: What smells like crank and cries like a little girl? (breaks his legs) Right answer!"
 * Eliot from Leverage gets one in:

"Mal: Looks like business ain't running so much as crawling away. You wanna meet the real me now?"
 * "Ore... SANJOU! From start to finish, I'm always at a climax! Let's go, let's go, LET'S GO!!"
 * Mal from Firefly gets an awesome one of these against Niska in "War Stories":

"Simon: Word of advice? Next time, take the trigger finger."
 * Simon Tam: Yes, she always did love to dance.
 * River Tam: You've always taken care of me... My turn.
 * FlashForward's Simon had a good one, after confronting the good that chopped off his finger.

"Psycho Red: We're the Psycho Rangers. Psycho Black: We're faster than you. Psycho Blue: Smarter than you. Psycho Yellow: Stronger than you. Psycho Pink: But we're evil!"
 * The Psycho Rangers from Power Rangers in Space have a pretty epic group one.

"Scott: Shh... You'll wake the baby. Ziggy: Yeah, and if you wake the baby, I might just have to sing you all a sweet little lullaby, and then tuck you into bed without any dessert, or even a single goodnight kiss... (notices Scott staring at him) Oh, wait, wait, what am I even saying. That... that didn't even make sense. I'm really sorry, um... kinda new at being a Power Ranger. I'm, I'm still working on my, uh... my hero one-liners, so... Scott: Look, Zig. I told you. They're called 'one-liners' for a reason. We're action heroes. When it comes to talking -- (Scott takes out three Grinders with a Capoiera kick) -- less is more."
 * Parodied, then discussed in Power Rangers RPM at the start of the "Ranger Red" episode, where Scott and Ziggy comes across a group of Grinders terrorizing a mother and her baby.

"Vampire Queen Afina: You're out of your depth, mongrel. Nikola Tesla: I'd rather be a mongrel than a stuck up, inbred bitch."
 * Boardwalk Empire: more of a Pre- One Liner—Chalky sits down with a Klansman and tells him a story about how his carpenter father was asked to build a bookcase by a white man, and after he worked long and hard on it, the man and his friends rewarded him for his troubles by Chalky then unrolls a set of his father's tools, and the Klansman nervously asks what he intends to do with them. Chalky just replies "Well...I ain't buildin' no bookcase."
 * SG1's Jack O'Neill and Atlantis's John Sheppard, both of whom are masters of this trope, with too many examples to mention. And the rest of their teams are no slouches either.
 * From Enos: A cop pops out of hiding and pulls a gun on two thugs, saying, "Your tax dollars at work."
 * From Sanctuary