Cool Educational Games

I am looking for a gift for Chirstmas son of my friend who is 9 years and spends most of his time playing on his PC. Well most kids do nowadays.

I am looking for suggestions for games that are educational, but fun. Then he can have fun and learn something good to learn. Perhaps one of the members site.

Thank you for your time and suggestions

well theres a game like this im twelve, but my brother ten years that he loves too much! Russian Tycoon's called! It is a kind of education I mean you buy a rollercoaster and build a park!