Also from the same episode, Meta Knight facing Kirby alone to prevent him from escaping was pretty damn badass. Even though Meta Knight was unsuccessful apparently.
Mario positively rules over this trope. Between taking on three rabid Yoshis and winning, then riding one into battle, taking on the entire police force on their own home turf with a freaking army, making fun of Link for running the place with a single Master Key ("Never put a Hyrulian in charge!"), riding Yoshi while using a Fire Flower to fend off Link, Sheik, and several armed guards, and fighting Link by himself with nothing but his bare hands. And that was in one episode.
Then, in a later episode, Mario is being menaced by a cult leader, Olimar. The moment is building up as the fanatics chant and Olimar approaches with a poisoned knife, and Mario is backed up against the wall... and then he floors Olimar with one punch. Then he delivers a massive speech to the Crowd, convincing them to fight not for some Eldritch Abomination, but for their kingdom and their future. Really, Mario is the ultimate badass in this series.
Mario is so awesome he can turn putting a bottle down into a Crowning Moment of Awesome. The bottle was alcohol, which Mario has had a recurring problem with. As Mario is about to take a drink, he sees a doll of his beloved Peach, and realizes what it is he's doing... and he puts the lid on and puts the bottle back down. It's an amazingly powerful moment for him.
Red gets one in Episode 9 when he stands with the others in confronting Ganondorf. An innocent Cheerful Child up until this point and visibly terrified by Ganondorf, he is nevertheless the very first member of the group to intervene in the standoff between Ganondorf and Captain Falcon, proving he is no mere bystander, and capable of being possibly the only honest-to-God untarnished hero in the groupseries. After the standoff, he even tries in vain to persuade Captain Falcon and Pit to stay and fight for the city instead of running away. That he gets killed right when he's shaping up to be a hero is all the more tragic.
Red: Get... out of... our... kingdom!
Bowser fighting off an army of Game & Watches, before blowing himself up along with them.
Tonight! This kingdom pays its debts!
There's actually an offscreen CMOA for Bowser and his army, when you think about it. Luigi arrives after the attack, only to find Bowser alive but poisoned, with some of his soldiers dead. The implication? Bowser and his troops fought off Ganondorf's army, Ness, Lucas, andthe G&Ws all at once, while most of their troops were on the streets. Hail to the King.
Many in the final episode, including Link's final battle against Ganon where he shoots lasers out of his sword after seemingly being killed, Leaf getting revenge on Wario with Jigglypuff, the entire brawl between practically every still living character in the whole series, and Luigi unleashing a massive green fireball by combining a red pikmin and a fire flower. Mario gets at least two more: beating a Smash Ball out of the Sandbag and launching the fireballs at the Game & Watch octopus, destroying it, and using a starman to take down about 20 enemies by himself.
Mario opening his wardrobe and wearing his hat and his cape for the first time in the series!
When Link finally says what we've all been thinking all this time: "SHUT THE FUCK UP, NAVI!"