Well, you have two options for Kirby. The first is the GBA version of Kirby's Adventure in Dreamland (NES). Basically an improved version of the old game. It has a different name, though, like Nightmare in Dreamland.
The other is Kirby and the Amazing Mirror, which is a completely new and very involving game. It has an actual, complicated map (unlike previous Kirby games), and that takes some getting used to, but it's an excellent game. Fun, challenging, interesting, visually attractive, and pretty long without becoming boring. It also has one of the coolest final bosses ever (though many of the other bosses are disappointingly easy).
Another aspect of this game is that there are four Kirbys (Mirror MetaKnight split the one into four). The other three wander around (really, you sometimes run into them, and you can see where they are on the map) while you play and you can call them using your cell phone (which has three uses, but battery power-ups are common) and they'll help you fight or solve a puzzle. If you're playing on a GBA and your friends have the game (I think you need it, anywway) you can hook up and play together instead of them being controlled by a computer.
So Amazing Mirror is pretty kickass, but the remake is much simpler. Depends what you're looking for. Personally, I recommend Amazing Mirror, it's an excellent game.