These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Kirby: Right Back at Ya!
Anvilicious: A good number of the episodes with morals are this.
Can't Un Hear It: Dedede's dub voice can tend to make some people think of the game Dedede with that southern voice.
Nightmare Fuel: It's Kirby, so several cases of this are to be expected.
Anticlimax Boss: Arguably, Kirby defeating Nightmare in the final episode. It takes less than a minute after exposing him to the Star Rod to defeat the "Emperor of Darkness" that had terrorized the majority of the universe.
In a rare instance of 4kids actually making better music than the original, the theme that plays when Kirby inhales something in the dub is an epic-sounding, heroic fanfare that reminds you just how hardcore American Kirby is.
Some music from Kirby Air Ride shows up in the Japanese original, as the game came out around the same time the anime was being produced. And any time a track from Air Ride plays, expect the scene to be awesome.
Ear Worm: The opening song of the English dub. It's almost as catchy as the DuckTales theme...
And then the ep where Fumu crushes on a Bifauxnen.
Magnificent Bastard: Meta Knight seems to show signs of this, even leaning more towards being a Guile Hero than in the games. Basically, he manipulates Kirby into getting pushed to his limits because he wants him to grow stronger that way. As he puts it, "Only then can he learn the true meaning of his power and turn the tides of battle." And what makes him even more magnificent? He's so charismatic that even the Cappies love him that much.
Despite only appearing in one episode, Amon, the rogue sheep who thinks he's a wolf, proved how badass he was as he took control of the sheep and took over both Pupu Village / Cappy Town and Castle Dedede. He can be considered perhaps one of Kirby's most dangerous opponents, shrugging off Needle Kirby's needles and having his own Near Villain Victory moment just before the whistle was blown to call back the sheep he had taken control of, plus he's one of the only villains not to lose his composure, even when his plans are foiled.
Recycled Script: The basic plot of the episode "Check it out! Channel DDD" ("Un-Reality TV" in the dub) is more or less a rehash of the Super Mario World episode "Rock TV". It's probably a coincidence, though.
Tear Jerker: Quite a few, surprisingly. It is heartbreaking when Kirby is genuinely sad.
The "little brother" robot puppy and Chilly. In both cases, someone who was sent to kill Kirby and ends up befriending with him instead, then dies because of Kirby, to save him in the case of the former, indirectly because of Kirby's actions in the latter.
In the beginning of the The End of the World as We Know It two parter, the villagers were complaining to Dedede for not building a town park and instead building a statue. Later, when the meteor was within spitting distance, Escargoon scolds Dedede for it, so then Dedede decides to take down the statue and build a park in order to redeem himself. After he builds it he grabs Kirby and brings him there. Kirby then jumps in joy and goes to play on the swings, then Dedede goes to join him.
The episode "Sentimental Kirby" ("Kirby Takes the Cake" in the dub). Kirby actually cries.
Woolseyism: Some of the name changes may be controversial, but admit it - Wolfwrath is a cooler name for a monster than Chilidog.