What do you think is a good and simple but not that expensive gift to a friend's 16th birthday?

i juz want to give her a gift! it's her birthday tomrrow, November 25! lol! she doesn't expect that! she's juz very nice! and we've been friends since grade 1 up to now, high school senior year!!! and i wan't to surprise her since it can be the last year that we're clmates!!! =)