I actually understand you quite well.
Someone once asked me, if there was a really smart Asian girl, who loved anime, Star Wars, all things ninja, was very smart and funny, and liked to wear schoolgirl uniforms... wanted me. But there was one problem. She was also a MS fangirl. I was asked what I would do in that situation.
I responded after thinking for less than half a second. I would tell her to get lost.

But I also mentioned that the odds of that happening were extremely remote, as I couldn't even get a white girl with none of those qualities, and at the rate Xbox is selling in Japan, I doubted if such a person even existed.
Anyways, I just wanted to empathize, even though I could probably live with a Sony fangirl. (It's funny... I can usually get along with Sony and Sega fans. Microsoft fans just seem retarded to me though. I only met one that I liked. I guess the diehard lamers are MS's target audience.

).
I would VERY much suggest getting her a GBA SP though. It might be a little more than a used GBA, but it would show that you really do care for her, and that's always a good thing. For a game... you would probably know better than us. But I think that the GBA would be a perfect "gateway drug" for a planned Nintendo invasion on her.

If you do get her a GBA, then you would have to make sure to buy Final Fantasy Crystal Chronicles the minute it came out, and have her over for long play sessions.
Anyways, so says this guy who is a 21 year old virgin. (and would appreciate it if this was never mentioned again.)