Epic Rap Battles of History: William Wallace does this three times in his battle against George Washington. When George points out that Wallace died before he was actually free, Wallace responds by painting his death as a Heroic Sacrifice while George died in a comfy home owning slaves. When George makes fun of Wallace's Cruel and Unusual Death, Wallace claims even if he was emasculated, eviscerated and beheaded he'd still be able to rip George's ass on the mike. Finally when George pokes fun at Scotland for being "only famous for golf and haggis", Wallace replies with this line:
Don't tee off with me, laddy! If you held my balls, you couldn't be my caddy!
Fallout: Nuka Break has the overweight Twig, a former resident of Vault 10, where being fat is the norm and skinnier people are bullied. As a result, anytime somebody tries to insult Twig for being fat, he takes it as a compliment.
If the Emperor Had a Text-to-Speech Device: Rogal Dorn is essentially impossible to insult, which comes in handy when the Emperor speaks offense as fluently as he does. He's Sarcasm-Blind to a ridiculous degree (because he simply won't consider the possibility people use it), so snark won't cut it. And if you outright call him an idiot?
It does bear mentioning that the one time an insult seemed to work, Rogal fired back with one ten times worse, shutting the Emperor up.
Jim Sterling from Jimquisition saw Digital Homicide mock his review of their (really awful) game The Slaughtering Grounds, punctuating just about every statement with "...because I'm Jim Fucking Sterling, son." Jim found it such a great phrase that he turned it into one of his catchphrases.
Luigi: You greedy guido bastard! Wario: That's Honorary Deputy guido, to you, now!
During Yogscast's first session playing Goat Simulator, Lewis wanted Simon (who is the one actually playing) to try for a double front-flip, which the game has up as its current suggested challenge. Then he realized that most of the challenges come in Easy, Normal, and Hard variants — with the double flip being labeled "Flipping Normal" — leading to this exchange.
Lewis: So now you've got the hang of that— Simon: I've gotta do two of those... Lewis: Yeah. And ideally three. Simon: What do you mean, "ideally three"? Lewis: Well, because Flipping Normal must be— Simon:You're flipping normal. Lewis: Thank you. Simon: Welcome.
Kiljoy: (sarcastically) Nice dress! Zinwrath: Damn right it's a nice dress! Brings out my girlish figure.
Yahtzee of Zero Punctuation fame is well known for insulting various groups of people or a specific person when he reviews a game. In his review of Quantum Conundrum, he mentions that he went to the Steam forums to look for answers as to how to tweak the game's settings (the game didn't have an menu to do so) and saw one poster who was basically the walking stereotype of PC gamers; the poster said that if someone doesn't know how to modify the game's internal files or if their PC can't even run the game, then they are not a true PC gamer. The poster then goes on to say that he would be honored if Yahtzee insulted him. And thus he did.
A popular insult (if homophobic, although whether they're seriously homophobic, using it sarcastically and aren't actually homophobic, or is insensitive depends on the person) is calling people "gay"/"homo" (in the same way someone may be "lame" or "dumb" or "retarded"), which can result in a comeback that the insulted party really is gay and challenges the insulter over how they really feel about that.
One joke is that a hidden message in the title of Super Mario Galaxy is "u r Mr Gay". Following a similar rule, the sequel's hidden message seems to be a reply, saying "ya i aM r u[?]".