Kirby Superstar is still the masterclass of Kirby. So I'll go with that. Wasn't as big on Forgotten Land as everyone else is. I know Kirby games are supposed to be easy but Forgotten Land's added Z dimension makes it almost impossible to lose. Nintendo also supposedly kept hammering HAL to include more enemies or to add some sort of added difficulty but HAL didn't budge. 

The game is gorgeous and the music, especially in Wondaria, is amazing. 

Return to Dreamland is also a favorite. I'm still more of a fan of 2D Kirby so I hope HAL continues to make 2D and 3D Kirby games like Nintendo still at least releases Topdown and 3D Zelda games. 

Edit: Thanks for the image btw, it's now my new Desktop wallpaper. 

^{Also... Kirby Star Allies. I know I'm going to get hate for it but it's one of my favorites.}

1 - Kirby Superstar
2 - Kirby Return to Dreamland
3 - Kirby Dreamland

The City Trial mode from Air Ride, peak video games.

Runners up for me would be Epic Yarn and Dreamland 3.

Epic Yarn is just so beautifully cosy and relaxing, the perfect game to play after a long stressful day.
Dreamland 3 is also just incredibly charming, and a worthy swan song for the SNES.

Kirby and the Forgotten Land has been such a huge step above the other recent entires, that I have to give it my vote. It is just a polished and solid experience that feels like a natural evolution of the IP.

Crystal Shards is my number 2 pick.

I don't understand why there's a bunch of people that dislikes Dreamland 3. It's not as good as Superstar, but it's also quite a beautiful game.

I wasn't aware there even was a lot of dislike for Dreamland 3. Can't see anything about it that would seem offensive or divisive. It's such a loveable and charming experience. Ah well, it's near the top for me anyway.

I do also really enjoy Superstar, Return to Dreamland, and Ghost Trap.