Elite Beat Agents is a very quirky rhythm/music game for the Nintendo DS. The game is extremely off-the-wall, as it follows a group of secret agents who help people with their problems through the power of music and dance.
The best part of this game is the song list. It has a great selection of rock and pop from the 80s to the present, everything from the Village People to Good Charlotte. I, personally, love the music, but you probably should only buy it if you don't like that style of music, since that's what the game revolves around.
The game is also very unique for a music game, eschewing the traditional "scrolling staff" style for a more free-form, touch-screen centered gameplay mechanic. Your hand can get tired after a while, and excessive play can eventually damage the touch screen, but it is overally a fery fun and engaging mechanic. I think that this game is one of the must-owns for the DS.