Personally i've found that Elite Beat Agent and Mario Kart DS are really good games for the DS which people at all ages can enjoy. If you're not really big with gaming Nintendogs is always a good one.
ummmm, well i would say basically anything that is not a tv show. Like cartoon network, or nickelodian, or disney channel. Only because they are REALLY short, and not worth the money. Trust me, ive learned the hard way!! But i would reccomend long games. Like pokemon, or nintendogs, or any of the sims games! Well good luck! hope you find what your looking for!