Mario Kart DS, personally. It's an extremely addicting racing game, especially if you have access to the internet at home. Playing it online is especially fun.
Animal Crossing: Wild World is a fun game, but it can get boring fast unless you're a huge fan of simulation games. Same thing goes for My Sims.
Mario cart Is more of a raceing game only played it once at a friends house and i dont like it
Never played animal crossings
My sims and my sims kingdom are very alike except kingdom is newer and more modern Well those 2 games are simply playing games and doing challenges to try to saver the town its fun but once u finish it u cant really play it agian so it waists money
If you are into my sims or my sims kingdom i would go for the newer one my sims party or my sims raceing
One of my favorite games is sims 2 pets apartment but like my sims once u finish it u cant play it Again
If your looking for a cheep game that dosent end try uno or wheel of fortune or deal or no deal not really a Challenge but it dosent stop going
also the best game for the ds is guitar hero so if u save a little more buy that game it so fun
By so Far Its animal crossing. well if you like multiplayer world online games but to do this you neeed wifi,if you like decorating getting pets etc this is a lifestyle kind of game
Mario Cart is allright its racing and you can vs other people by wifi connection
So i reckon that you should just buy animal crossing