Nintendo DS has a bunch of great puzzle games but the Brain Age series, Tetris and Sodoku are at the top of my list. Planet Puzzle League is supposed to be fun too but I haven't gotten around to that one yet.

I liked Bust a Move where you match and connect different colors.

If you like cute Japanese animation, Puyo Pop Fever is a good game. The Puyos fall like Tetris, but they pop when 4 of the same color touch each other. I have the Japanese 15th Anniversary edition. It has many creative modes and it is really fun. It works fine on my US DS console.

I'd reccomend Legend of Zelda: Phantom Hourglass. Cute story and characters!