chess set and board, books, construction kits, tinker toys, anything that involves the child in doing something except sitting on his backside staring at a video screen and twiddlling around with a games consul and turning his brain to jelly.
I would have to say either sporting goods, so a soccer ball, baseball, soccer cleats, etc.
Or Legos were always a favorite of mine, although at 12 I think I was starting to grow out of them. Maybe a skateboard/snowboard or something of that nature, or if you live by the beach I think a skimboard is a great choice... I learned how to skim board at 10 years old and I love it.