My kids and I tend to like things done graphically well.
https://secure.brainpop.com/ This has very nice graphics.
My kids have not been interested in this website and I'm not sure why. I like how they incorporate movies. I also like how there are many options to encourage more learning within subjects.
http://www.mathletics.com/ This is a competitive way of learning. My DS9 loved this.
http://www.oldtrail.org/libraryclassresearch.htm. this is a lost of Path finders, leads to sources of information for research and learning.
My son did an online course thru Northwestern university and found the class chat to be a good learing experience.
Hope this is helpful. Good luck
