I have an 8 year old and she loves Tootsville* and all the games. I love that they are more educational than most of the free sites on the internet and she also gets to learn the value of money as she shops for things in the stores. I'm very happy with the content and security level of the site -- I set time limits for her and they also allow me to monitor her account from my own parent account (not that I don't trust her...it just makes me feel more comfortable).
It's a great website, but here's the problem.
A girl invited me to their house. They were looking for a boy. I said I was a boy. The girl made the heart emote at me and then said 'who's a boy'. Then a user named flappy came in and said a sexual swear word in a really clever way. That's the only problem.
But it's a great website with great user content! Just watch out for those sailors...