Alas! If you are reading this guide, you must be a parent in a panic. Either that or you're a teenager looking for suggestions on what to demand from your long-suffering parents.
Basically, this is a quick guide on what's good for your teenager. You may pick up a repetitive theme here.
a.) Money - cold as it may sound, most teens prefer money. It comes in handy when great things come up on eBay *Cough Sony Vaio* or just for general clothes shopping. If your teen demands money, give it to them! No person has ever been disappointed with a little extra cash (unless it's not enough! You have to walk the fine line between skimping, and spoiling!).
b.) Their Saving Target. Okay, let's use an example I've already mentioned, a Sony Vaio laptop. In fact, let me be factual here. I'm $1200 towards a $1600 Vaio. Again, it's money, but in a more 'gift' sense. You contribute the remaining dollars, and hence, technically 'buy your teen a gift'. Kinda.
c.) Yes, money again! Except this time, your put it into an account they can't get their greasy little paws onto. They'll hate you for it, good heavens, their friends will hate you for it, but come the time when they want a car or a house, that little extra cash can go a long way.
By the way, the recurring theme was money, did you get it?
Money is not the only thing teenagers want, but it's the best thing I can suggest that's suitable for both sexes, and 95% of teenagers at least want it. It's a pretty safe gift.