For language I can't recommend the Rosetta Stone system enough. You may think it is pricey but when you are done with it, it can be taken off of one computer and registered to another. Therefore there is a resale value.
I used the Core Curriculum for elementary grades. It is the best that I have ever seen. The explanation of math is clear and understandable. The history is alive and told in a personal story telling style. The information from year to year is integrated to build on each other like stacking...