My kid (10 years old) enjoys to play at Eggochi World. Eggochi World is a Virtual world for kids which is free and grants them various values. They can pick one of the characters in the Eggochi world and start to grow and take care of it. This way, children get a sense of responsibility. They need to feed the character in time,keep it clean, look for it's health and give it love. The address of the site is : www.eggochi.com
My favorite virtual worlds are www.poptropica.com .It's fun and educational.My other favorite virtual is www.moviestarplanet.com .It's really fun.Make movies and be famous.Both moviestar planet and poptropica are good for kids.