PBS Kids- Wonderful online fun, lots of learning games with their favorite characters http://pbskids.org/
Brain Pop- A site that makes any subject fun, great for older kids http://www.brainpop.com/
*Starfall*- Exciting and fun website for kids of all ages in elementary! http://www.starfall.com/
FunBrain- Lots of games for all ages! http://www.funbrain.com/