Kirby gets one at the end of Milky Way Wishes in Kirby Super Star/Ultra, when Marx tricks Kirby into awakening Galactic Nova, a mechanical comet with the power to grant wishes, and leaves Kirby for dead, in an attempt to take over Pop Star. Kirby assembles the Starship, and flies into Galactic Nova through a level that plays like a Gradius style shooter, destroys the craft, and crashes onto Pop Star for a final, epic duel with Marx to decide the fate of the planet.
He gets an even better one when, in Revenge of the King, as he goes to the final level, Dedede shoots him down with KABULA, a character who hadn't appeared in 12 YEARS, as Kirby falls down helplessly... and assembles the Starship out of the three stars he got before from the three previous bosses! Cue amazing shoot 'em up boss fight.
King Dedede gets one when he teams up with Kirby in Kirby 64.
And how can we not forget the most epic quote in Kirby Super Star Ultra? When Kirby finally makes it to Dedede, who sent minion after minion — even Captain Waddle Dee — after him, he tells Kirby to arm himself with a Hammer, and then says this:
Our grudge will be settled at last...
What is possibly his greatest CMoA comes near the end of Kirby's Adventure/Kirby: Nightmare in Dreamland. After spending the whole game thinking Dedede's the Big Bad, the player learns he had been trying to seal away Nightmare the whole time. Even after getting beaten into submission, he gets up shortly afterwards to try and stop Kirby from putting the restored Star Rod into the Fountain of Dreams, going so far as to be dragged across the ground part of the way there. As if this setting the tone for his behavior in the future wasn't great enough, he ends the scene in a somewhat badass way — He swallows him and the Star Rod, then spits them back out. Into space, to deal with Nightmare.
The final boss of Kirby 64 was a Crowning Moment Of Awesome for both Ribbon and Kirby: they face off against the embodiment of all evil together, armed only with the holy crystal of the fairies. Oh, and did I mention that Ribbon actually CARRIES Kirby throughout the whole battle? She doesn't even drop him if they get hit! Her wings expand to 3 times their size, just so she can carry our favorite pink hero! And afterwards, she kisses him, which causes him to faint. (This is his only kiss with ANYONE in the whole series!)
Kirby's Dream Land has an awesome ending, too. Kirby defeats Dedede, TURNS INTO AN ENORMOUS BALLOON, and brings the food back to Dreamland. How awesome is that?
The ending of Dreamland 2 was nothing short of memorable, if not counting as both CMoA and Crowning Moment of Heartwarming. After Dark Matter transforms from a katana-wielding warrior into the one-eyed monster we recognize, Kirby fights him with the Rainbow Sword in outer space as they slowly descend into re-entry through Dreamland's atmosphere. Kirby defeats Dark Matter but seemingly passes out due to exhaustion. A cutscene shows Coo glimpsing a shooting star while the rest of Kirby's animal helpers watch the sky as somber/hopeful music plays, and even Dedede is shown wondering about the fate of our hero. Kirby wakes up, only to find out he has been floating down safely thanks to the power of the Rainbow Sword, which Kirby grabs and flies around with as day breaks and the credits roll. If played on the Game Boy, the streak of light that comes from the sword at the last moment appears as a rainbow. Cue end. The entire sequence can be seen here.
Listing all of Meta Knight's awesome moments would be insanely difficult... But let's try anyway! Well, Meta Knight basically slaughters his way to Galactic Nova, the wish-granting comet, and asks for his wish. What is this wish?. To put it bluntly, he unleashes a Godlike being that was sealed away due to being too powerful and proceeds to kick its ass in a way that would make Chuck Norris cry. Why? Partly because Meta Knight just wanted to become stronger and mostly for the sheer hell of it. If that's not Bad Ass, then nothing is.
The Final Battle cut scene in Kirby's Return to Dream Land. Everyone is riding dragons through a wormhole, dodging energy balls shot by the Big Bad, and Meta Knight is zipping around batting them away with his sword like they're nothing. He only gets shot down when he flies in front of Kirby to protect him.
Shadow Kirby gets a small one in Amazing Mirror. Having been just an occasional enemy that would sometimes attack you and generally perceived as evil, if you lose Meta Knight's sword during the really long SequentialFinal Boss battle, he will go get it for you during the final battle. Even if it breaks during it (therefore reappearing in its place of origin).
Marx gets one of sorts... He's killed after crashing into Galactic Nova, drifting through space, but his soul, out of anger and pure madness, absorbs the entire power of said wish-granting comet and resurrects as an even more monstrous Eldritch Abomination just to kill Kirby at the top of the True Arena.
Marx gets an amazing one. After tricking Kirby into summoning NOVA, he pushes Kirby aside and wishes for control over Pop Star. He then turns into an Eldritch Abomination as a result and flies off, but not before sharing this tidbit with us:
Through the magic of Fridge Brilliance, there's a major Crowning Moment Of Awesome in Kirby: Canvas Curse. Consider the intro, where it says that the titular Power Paintbrush "is transported to you on a ray of light". You hold the stylus... I mean paintbrush. Now, think about the final battle, against Drawcia Soul. She is defeated by tapping the Para Matters she sends out with the stylus, and then when she moves into the foreground, simply poking her with said stylus until she is stunned, leaving her vulnerable. Kirby barely touches her at all except for the final blow, everything else he does is dodging her attacks. Now, put these two things together and what does it mean? YOUWERE THE ONE WHO DEFEATED DRAWCIA!WITH HER OWN STYLUS!!! Talk about involving the player in the game!
The best part? It doesn't have to be Kirby to land the final hit. When she's in the foreground, tapping on her deals a little bit of damage. The result? If her HP is low enough, you can defeat Drawcia just by tapping on her with the stylus.
In Kirby's Return to Dream Land, any time you use one of the 'Super' copy abilities, this happens. However, late in the game, you take Kirby through every single miniboss with the Ultra Sword, defeating them each in one hit, and a couple of the bosses are defeated with the Ultra Sword, and it is awesome whenever it happens.