Many educational resources from the BBC - separated by level. Although with a "British" twist for vocabulary, well worth checking out. The "questionnaut" on the KS2 Bitesize page is quite different than typical US review games.
Stargazing Live is a wonderful BBC programme on air in January. The site has lots of great resources to help you understand the night's sky.
http://ictmagic.wikispaces.com/Science
An interesting interactive resource from the BBC about the importance of using interesting vocabulary and adding 'bling' to writing.
http://ictmagic.wikispaces.com/English
I love this site from the BBC with stunning visuals and a great soundtrack. Travel through a strange world answering questions about English, maths and science earning fuel for your hot air balloon. Click on the characters to unlock the questions. Designed for KS2.
http://ictmagic.wikispaces.com/Cross+Curricular
This is a superb site from the BBC with interesting questions to inspire awe and wonder. There are videos and other media which attempt to answer questions on history, science and much more.
http://ictmagic.wikispaces.com/Cross+Curricular