She mentioned that she might like a spa treatment but that crap is highway robbery. If I send her in there with $100 gift certificate, she'll get a half-ass back rub and they'll dangle all of the other services in her face that she's not getting.
She loves to cook/bake, draw, dance, watch movies (comedies and vampire stuff), listen to music (dubstep), go to the beach, and spend time with friends & family.
Most Helpful Girl
You could get a lot of little things and put them in like a "gift basket" type of thing for her. I think that would be sweet and show a lot of thoughtfulness. Maybe get her a new baking recipe book, some new tools to draw with, buy her favorite movie on DVD or BlueRay or whatever, put together a playlist of some songs she really likes, you could always go on like a day trip somewhere like the beach or where ever her favorite place to go and have fun is.
Most girls don't really care about the monetary value (at least I don't), I know it's cliche but it really is the thought that counts. As long as you put some effort and thought into whatever you get her I'm sure she'll love it:)