Kirby and the Crystal Shards for the N64 is, in my opinion, the best Kirby game out there. It is also the game where I was first introduced to Kirby. I first played this game at Mike Albaine's house. At the time, we were playing the multiplayer portion of the game, specifically the one where you try to make the other players fall off of a platform by making the blocks they are standing on fall from underneath them. When I finally got an N64 myself, this was one of the first games I bought. I did not buy it though for the story mode, as I had never actually played this myself. Eventually though, I did end up loving this part of the game also.
My most recent accomplishment in this game was 100%-ing it, a feat I greatly enjoyed. Not only did this involve collecting every crystal shard, it also unlocked an additional boss, and a quite epic one at that.
This game as a whole? One of the best.
-=*I Love Kirby*=-