Spore

I don't intent this to be a commercial and I'm certainly not getting any money for this but I can't help being pretty enthusiastic about the game "Spore". I'm not a big gamer but the ability to create your own monster is irresistible. Check out this little vid I found on YouTube and then go to the site and play the tutorial: http://www.spore.com/what/screensmovies#creator
Fun!