Lobo's introduction in Superman: The Animated Series. "The name's Lobo. That's 'L' as in 'Lacerate', 'O' as in 'Obliterate', 'B' as in 'disemBowel', and 'O' as in... Eh, I guess I can use 'Obliterate' twice, huh, what do you think?"
Justice League Unlimited also had a huge subversion. When Doomsday came to Earth and fought with the Justice Lords, (an Alternate Universe Knight Templar version of the Justice League) he began a Badass Boast while doing a Neck Lift on the alternate version of Superman about how tough and indestructible he was... and then the alternate Superman lobotomized him mid sentence before Doomsday could finish.
Doomsday: (Lord!Superman punches him) You think that could hurt me!? (stomps on Lord!Superman) My skin can withstand a nuclear explosion! (Neck Lifts him) My bones are... (Lord!Superman fires heat vision into his head) my booooones...
Livewire: "You can't stop me any more than you can stop wind... rain... or lightning!"
Superman: (to Darkseid) Any minute now, Brainiac would explode. And guess what? You're going with him.
Darkseid: "Super or otherwise, you're merely a man, whereas I am a god." Also: "I am many things Kal-El. You couldn't begin to imagine half of them, but for now I shall take the role of executioner." And finally, "I want you to understand Kal-El, that from this point on everything that happens is on your head. The skies will rain fire, the oceans will boil, the streets will run red with the blood of billions. Only then, when your last pitiful hope is extinguished will I end your life. Let's go."
"I am many things, Kal-El. But here, I am God."
Lex Luthor, when told that only a twelfth-level intellect can retrieve the Anti-Life Equation: "Then I'm overqualified."
And this exchange between Wonder Woman and Superman while they and Green Lantern charge the flagship and support of an alien army that had defeated them before:
Wonder Woman: "Pretty bad odds."
Superman: "Yeah. They don't stand a chance."
J'onn from Justice League Unlimited's "Task Force X": "Ask yourselves, is being in here with me what you truly desire?"
Zuko delivers one in his A Day in the Limelight: "My name is Zuko, son of Ursa and Fire Lord Ozai! Prince of the Fire Nation and heir to the throne!" It has the intended effect on his opponent... but unfortunately it also has the side effect of making the people he was defending hate his guts. Whoops.
Made worse by the fact that these people were rooting for him while he was fighting the Earth Kingdom soldier.
Earth Bender: "Surrender yourselves! It's five against two. You're clearly outnumbered."
Uncle Iroh: "That's true. But you are clearly outmatched."
Something memorable from Azula's first speaking moment in the 2nd season..
Azula: "Well, then, maybe you should worry less about the tides, who've already made up their mind about killing you, and worry more about me, who's still mulling it over..."
This was actually part of a sequence of "sides", which are lines written for actor auditions, but not part of the actual script. The dialogue was so good that the writers put it in the show.
Aang (speaking with the combined voices of all of the Avatars): "Fire Lord Ozai! You and your forefathers have devastated the balance of this world. And now, you shall pay the ultimate price!" ((Said while combining Fire, Earth, Water, and Air into a very powerful spear thing))
Quite possibly the most awesome one in the series happens after Azulaout gambitsLong Feng and turns his own men against him, thus taking over an entire city with just herself and two "friends". She delivers this badass quote:
Vaatu gets a good one in the two-part episode "Beginnings."
I lived ten thousand lifetimes before the first of your kind crawled out of the mud. It was I who broke the bound the separated the Spirits from the material world. To hate me is to give me breath. To fight me is to give me strength. Now prepare to face oblivion.
Derek Powers, aka Blight, of Batman Beyond delivers this one in his first super powered appearance while giving Mr. Freeze a beatdown: "And behold, I shall be a blight upon the land, and everything I touch shall wither and die."
Batman ties up the Repeller and explains his bonds are, "Titanium. The strongest alloy known to man. It's unbreakable." The Repeller replies, "Nothing's unbreakable if you apply enough force!" He proves it.
Sam's line "An' I ain't no namby-pamby" was a dub-over of the original line, "An' I don't mean Mahatma Ghandi!"
Megatron from Beast Wars, being the Large Ham he is, delivers one of these in the Grand Finale: "I am Alpha and Omega, Optimus Primal. Until the End of TIME!"
Before that when he was on his A God Am I power trip (well, started it.)
"I am Alpha and Omega, the beginning and the end. I am that which was, which is, and is yet to come! And you will know my name is MEGATRON, when I lay my vengence upon you!"
Almost everything he said in that episode was a badass boast. But the finale in Season 2 [The Agenda Part III] had two more badass boasts.
"So, we are now face to face, Optimus Prime. In one future you awaken and become the great leader of the Autobots. But time shall take a different track, now... computer! All available power to primary weapon! ... And now, Optimus Prime, in memory of the Decepticons... for the glory of the Predacons... for the Cybertron that is rightfully ours, and mine to rule! ... I unleash the storm of vengeance — farewell!"
"Say goodbye to the universe, Maximals! The future has changed, yessssss. The Autobots LOSE! Evil TRIUMPHS! And YOU...! YOU! NO! LONGER!EXIST!"
As another example from the same series, henchbot Inferno was attacked by newly-decanted Quickstrike, and responds with "Fool! Pain is my friend! Allow me to introduce you!"
Slade: No, Robin, I won't stop. Not now, not ever. I am the thing that keeps you up at night. The evil that haunts every dark corner of your mind. I will never rest. And neither will you.
Sleeping Beauty villain Maleficent, right before going all One-Winged Angel: "Now shall you deal with me, O Prince... and all the powers of HELL!" Complete with reaction shot from Prince Philip, looking like he's just soiled his pants.
And a little earlier: "You poor, pitiful fools, thinking you could defeat me — me, the Mistress of all evil!"
Ultraman gets a number of these, which straddle the line between Narm and awesome.
At the end of "Twilight", the second season premiere of Justice League, the supervillain Darkseid lies buried under debris, trapped in an asteroid which is about to go out in a massive explosion. To his growing dismay, his adversary, Superman, escapes through a Boom Tube. Witnessing this, now stranded alone and facing death, he has just time to sneer, "Loser."
Actually, Superman was dragged through the Boom Tube by Batman. The boy scout had every intention of breaking character just for this one chance at killing Darkseid, who uttered the above quote as more of a response for Supes being denied his revenge.
And in part 1 of the series finale, "Destroyer," Darkseid lives again - and expresses his appreciation to those who have inadvertently caused his resurrection:
Darkseid: Although your planet will die screaming, I grant you the gift of a swift death.
Hak Foo of Jackie Chan Adventures explains why he isn't using the superpower-granting talismans that he was given after Shendu's defeat: "The horse for healing? I am not so easily injured. The rooster for levitation? I already fly. The dog for immortality? There isn't a man alive who can vanquish me!"
ReBoot has a pair of these one after the other. First is Matrix right after sparing Megabyte.
Surprised? Don't be, you're not worth it. Mainframe will always endure. Remember this defeat, this humiliation, and know that you can never win.
Megabyte responds to this by pushing himself off the building and then saying: No, you remember, boy. How I turned defeat into victory. How I left you with a dying system.
Apocalypse from X-Men has a few. One of the most notable is "I am not malevolent, I simply AM!" followed by him backhanding Cable or Bishop through a wall.
There's also his statement to Graydon Creed: "I am as far beyond mutants as they are beyond you. I am eternal."
"Beast, how many peoples have dreamed of my end? You are no closer than the Babylonians with their swords and fire sticks!"
"I am the rocks of the eternal shore. Crash against ME and be BROKEN!"
"There exists no freedom from me. There is only freedom THROUGH me."
And then from A Canterlot Wedding - Part 2, Princess Celestia delivers the most badass line in the entire series. But sadly she ends up losing the fight against Queen Chrysalis.
Queen Chrysalis: Soon, my Changling army will break through. First, we take over Canterlot, then all of Equestria!
Princess Celestia: No, you won't. You may have made it impossible for Shining Armor to cast his spell, but now that you have so foolishly revealed your true self...*cue charge*...I can protect my subjects...from you!
In My Little Pony And Friends, back before you'd ever imagine anything could ever be Badass about this franchise, "Bright Lights" has a point where the ponies figure out how they might stop the Big Bad, but "that would take an army." Megan brings one: the flutter ponies. They get an entire song consisting of Badass Boasting as they deal with the bad guys who once stole the shadows and thus the Life Energy of an entire town in no more time than it takes to sing it:
We are the Flutter Ponies - better run and hide!
We can zig and zag and zoom up and down and side to side
We are the Flutter Ponies, now you've met your match!
Faster than a lightning bolt, we're impossible to catch!
Too bad for you we found you, for soon as we surround you
Reg: Go on ahead inside, sorry to keep you waiting!
In Spider-Man: The Animated Series, Morbius taunts Peter for being late for classes the day the students start a science competition. In retort Peter references "the Tortoise and the Hare" parable to which Morbius imperturbably responds that "In my country we eat tortoises."
Black Beetle gets a simple but effective one. When told that if he cooperates the Team will go easy on him, he just starts laughing.
Wonder Girl: Listen, ahh...Black Beetle! You're totally outnumbered. Open those doors, and we'll go easy on you! Black Beetle: You... will go easy? On me? Hehehe hahaha... HAHAHAHA!! Bumblebee: Oh, that is not a good sign.
In Ben 10: Ultimate Alien, Ben confronts the Forever Knights when they begin systematically hunting down and killing aliens (though they offer then a chance to leave the planet first, they're not very considerate about the aliens' ability to procure transport). He challenges the leader to a duel to get them to stop, but the leader goes back on his word. Ben's response is as follows:
"Maybe you forgotten something: I'm Ben Tennyson, wielder of the most powerful weapon in the universe. I stopped the Highbreedinvasion, I defeated Vilgax in hand-to-hand combat and I've beaten the Forever Knights more times that I can count. Here's what's going to happen: you're going to release these prisoners, you're going to crawl back to whatever hole you came from and you're going to stop hunting down aliens because if you don't, I promise, you'll regret it for the rest of your very short lives."
Needless to say, they backed down after that, and haven't tried it since.
Aqua Teen Hunger Force gave us the Memelicious boast from Carl, when, after stealing the Foreigner Belt from the Mooninites, the Mooninites state that Carl can't use it since he doesn't have the instructions. Carl's response?
In American Dad!, Klaus gives one to Steve in Roger after they prank him.
Allow me to impress upon you the severe mistake you have made. For years my conduct has been largely benign. And yet, without provocation, you have severed our détente and forced me to unleash upon you the vengeful flames of a thousand suns. You shall curse your mothers for the day of your birth. So, go now, go, and begin your life of fear, knowing that when you least expect it, the looming sword of Damocles will crash down upon you, cleaving you in twain and as you gaze upon the smoking wreckage that was once your life, you will regret the day you crossed the WRONG FISH!!
In the Static Shock episode "They're Playing My Song", a crooked music producer gets arrested. As he's being led into the police car, he boasts, "You think I care about jail!? It will only give me more street cred! When I get out, I'll be a legend!" Static counters by saying that by the time he gets out of jail, he'll be old, which scares him.
In the Super Best Friends Forever short "Grounded", when Supergirl is fighting Superman when the latter is trying to enforce the former's titular punishment, Supergirl cries out "You're not my father! You can't tell me what to do!" Superman's response? "No, but I'm Superman and you'll do as I say!"
X-Men: Evolution from Cyclops "We're the X-Men, Wolverine. We're not kids anymore. You trained us; and you know something? We're good... we're very good."
In the Rankin-Bass adaptation of The Hobbit, Smaug the dragon's boast to Bilbo gets an additional boost from being voiced by Richard Boone.
Yosemite Sam: "Any one of you lily-livered, bow-legged varmints care to slap leather with me? In case any of ya get any idears, ya better know yer dealin with. I'm the hootinest, tootinest, shootinest, bobtail wildcat in the West! [fires guns, raising Sam up] I'm the fastest gun north, south, east annnnnnnd west of the Pecos!....I'm the...." Bugs Bunny:' "Ahhhh, shaddup!"