Though I disagree with your mom, I will get the black one.
I'd buy Super Street Fighters IV as first game, if I liked the genre. It looks great (I love the art style) and seems to be an excellent game. Unfortunately I don't like fighters, but maybe you?
If none of the launch and early titles interest you enough I recommend to use the 3DS just for Pokémon Black/White until Zelda OOT, Paper Mario or some other 3DS games you really want are released.








