Thanks everyone,

He does have quite a few games he plays, and enjoys but there was something he found facinating about WOW that had him enthralled. Maybe partly that his parents play it *blush*. I'm really after something where he can wander around in first person and explore a bit, maybe with puzzles and things. People to talk to would be good. I thought the newer Myst, but I think the puzzles would be a bit over his head.

Those games look good to add to his collection and/or bookmarks. He is a science-y child. I think he would really go for some of the Sims games too, I'll have to investigate those.

If there are any I can introduce as "a kids version of Mamma's game", that would be great.