In No Rest for the Wicked, Perrault tells November "You could always turn around and go home." Then, they meet Red. Somewhat later, following her through the woods, November repeats the line to Perrault.
A Miracle of Science has two, "That, gentlemen, is the sound of conquest" and "Behold, the Martian invasion fleet." The first one is used by Ben first in the flashback as a Mad Scientist trying to take over the moon, and later by Ben when he is confronting Haas. The second one is used first jokingly by Caprice, but then seriously by Ben in the end.
"I'd be tempted to say this is impossible to say that this is 'impossible', but that is a word used only by idiots who lack the patience and reason to consider their own surroundings." ... "Impossible!"
In The Order of the Stick prequel book Start of Darkness, wizards repeatedly act condescendingly to Xykon, a sorcerer; wizardry, which comes through study, is like a "finely-tuned watch," while sorcery, which comes naturally, is unwieldy like "a rubber hammer." Later, when Dorukan uses the same line, Xykon repeatedly hits him with Energy Drain spells, making Dorukan's own magic impossible while slowly killing him. Xykon points out that even if his magic is less sophisticated, the fact is that at a certain level of power no strategy can work against you, and right before killing him mocks that Dorukan can "keep [his] finely tuned watch — Give me a sledgehammer to the face any day."
Also, in the Greysky City arc, Haley derides Celia's Thou Shalt Not Kill attitude, and tells Celia to back up, because she was "going to betray [Celia's] principles all over the friggin place." Later, when Celia makes a deal so everyone lives but Haley retroactively owed 50% of everything she ever stole, Haley furiously asks if Celia knew what she had just done. Celia snaps back, "If I had to guess, I'd say that I betrayed your principles all over the friggin place."
During the battle in the desert with Tarquin's gang, Elan says that Tarquin can't kill Roy without going through him. Tarquin replies "You're still at full hit points, right? You'll live." When Elan lets Tarquin fall from the airship, the last thing he says to him is "You'll live."
In "Kiki's Virus", Dr. Schlock captures Kiki the talking ferret and threatens to dissect her, and she says "Don't hurt me! I'll be good!" Then Sam — Kiki's former owner and now a vampire — shows up and picks up Dr. Schlock, prompting him to say the exact same thing.
"Weird girl, Sasha" gets repeated over and over again by almost all the (sane) characters... and then Sasha gets a chance to throw it back at them : "Weird guy, Torg"
In thisDominic Deegan strip, Rachel, an athletic female friend of Gregory's, goes to break up a fight between him and the bigot slaughterball player she used to idolize, Brett Taggerty:
Rachel: I don't know what's going on in here, but I suggest you let go of my friend and explain yourself. Brett:(lets go of Gregory and raises his fist) Yeah? How about I break your face instead?! Rachel: I invite you to try, Taggerty. (Brett promptly punches Rachel in the jaw, eliciting a "KRAK"; but in the next panel, he's got a bloody hand) Brett: AAAAAGGH! Rachel: I break things with my face.
In the second arc of The Wotch, Anne accidentally turns Jason into a Jean Grey spoof, prompting Robin to tease him with, "At least you're hot. He he. I mean, you can provide a real distraction!" Nine arcs later, Robin is turned into a large-breasted girl to act as a crowd control diversion, prompting Jason to snark, "'At least you're hot.' 'You can provide a real distraction!'"
Zebra Girl: "Doesn't it worry you that I'm not worried?"
In the Touhou fancomic Tag Dream about a tag-team professional wrestling-style tournament, when Flandre and Meiling fight Sanae and Suwako, Flandre launches into a technique designed for fighting extremely physically tough Oni to use against the human Sanae. Meling warns her that they'll be disqualified if they kill an opponent, but Flandre says losing like that would be fine. Later in the match, with Sanae unconscious and receiving medical treatment, Flandre weakened by garlic, and Suwako systematically breaking Meiling's bones rather than pinning her, Flandre tells Suwako to stop or Meiling might die, and Suwako says losing like that would be fine.
Bobwhite, this comic. Marlene, a film major, has nothing but complaints about a movie they just saw. Georgie, unconcerned with the technical aspects, thought it was pretty good and doesn't see why Marlene's so worked up. They go to get a burger and suddenly their positions are switched.
Archipelago: Credenza and Raven have a bit of back-and-forth in Book 7, involving the line: "Of course. It's only okay when you do it."