Two quick recommends

1.  Viva Pinata: Pocket Paradise (I caved) and Lock's Quest.  Both quick "buys."  Pick 'em up now before the flood of DS titles drains you dry.  Upcoming:  Korg-10, SimCity Creator, My Japanese Coach, Grand Theft Auto: Chinatown Wars, Guitar Hero: Decades.  Just doesn't end.  The DS is going to be going strong for years.  Must be why they haven't even considered DS II yet.