Nihilus: You know what the biggest difference is, between you and I, Luna?
Luna: Wings and a pretty face?
Nihilus:Showmanship. I demolish half a dozen buildings arriving in a flying castle that casts an ominous shadow over half of the central plaza. You only arrive after I give you a perfect entrance cue, and even then you just trot on up to me as though Im a casual acquaintance. Itís insulting, really.
*sun goes out.*
Luna: Go on again about casting an ominous shadow.
Pinkie blocking and dodging all of Wrong's attacks.
Rarity's to Sir Unimpressive, in typical Rarity style:
Rarity: Yes, I am knight commander, and if you would like to duel the only pony alive who has been trained by both the strongest mortal bladecaster and the god-princess sitting behind me, you will find out why. As a non-magical talent a decade your junior, I will happily embarrass you in front of your friends. And I will look absolutely fabulous doing it.
And then there's the actual final duel between Titan and Twilight who's absorbed Harmony's powers and become a god. While the entire thing is mind-blowingly awesome, one moment that sticks with this troper is when Twilight punches Titan in the face hard enough that his head implodes (he regenerates, but still).
The Climax Boss battles with Nihilhus, Esteem, and Terra, each one more awesome than the last.
Rainbow Dash managing to break free of the Insanity, saving Pinkie's life, and then going apeshit on Nihilus. It's made even MORE awesome when Twilight reveals that Rainbow had SO MUCH Undying Loyalty to her friends that Nihilus had to use 7 TIMES the amount of energy that the spell would normally use, and that Rainbow Dash managed to retain her sanity afterwards is remarkable!
Twilight Sparkle's She's Back moment when Titan accidentally fuses her mind back together. Mostly an Offscreen Moment of Awesome, since she apparently takes out one of Titan's avatars in the process, but we don't get to see it.
Valiant proposes to Astor Coruscare, with severed head of the most powerful dragon ever live that he'd slain (with Luna's help), as engagement gift. His love and devotion for Astor is the catalyst of her redemption.