Need help.
Well she is you bestfriend. so dont you know what she likes? give her like, a gift card to her fav store or something, or do what abbyness said. give her some cash. but she sould like whatever you get her. juts as long as its not repulsive! :P lol
DVDs, a pet hamster, some novelty sweets, take her out for milkshakes/icecream or something maybe...
just give her money so she can buy anything she wants :P
how much do you wanna spend is the first question.