City Trial is a masterpiece of a game mode. Played this one so much as a kid that I'm almost sick of it, especially since my sister still asks to play it with me whenever she's over.
Kirby: Nightmare in Dream Land
My first Kirby game. The music and visuals will forever be part of my soul.
Kirby 64: The Crystal Shards
Kirby's Dream Land 3
Kirby's Star Stacker
Kirby Super Star
Kirby's Block Ball
Kirby's Dream Land 2
Kirby's Avalanche
Kirby's Dream Course
Kirby's Adventure
Arguably has a better art-style than NiDL, but the slowdown and clunkier controls make it less enjoyable overall. Still one of the best NES games tho.