My daughter will be 14 in December. We have Christmas and birthday within 2 days of each other.
We got a Wii right after they came out a year or so ago and it is a HUGE hit with her and her friends. We added Guitar Hero with 2 guitars and they have a blast.
We plan to get the Wii Fit for 1 of her gifts.
Wii's can still be hard to find but I saw 3 at Blockbuster yesterday with all the accessories (golf club, boxing remote, steering wheel, etc)
About 2 yrs ago, we bought her a very nice pendant and gemstone ring. We upgraded those this past summer to larger pieces and she goes no where without her necklace and ring. She did choose the pieces herself so she could get what she loved.
We gave her a Coach purse a couple yrs ago that she still uses. She has 3 of them now in assorted sizes. The girls her age love Coach, Ed Hardy, Juicy, etc
Another favorite os hers is gift cards and/or $$$ She loves to shop!
Melanie's daughter sounds a lot like mine. Mine loves the SIMS as well for her laptop as well as the Wii.
Also, the series of books by S. Meyer beginning with Twilight (movie comes out in Nov) are a huge hit with the readers in middle school. My daughter and most of her friends have read them all and LOVE them. I have never seen my daughter be so "into" a book. As she finishes the books, I read them and they are good.