Most people seem to know about Math U See. It has worked well for my son who is on the Autism Spectrum. It has really helped him to learn math. He is doing much better as he progresses through the program. It is not a program that I would have personally liked as a child, but it seems to be a good fit for many students.
The positives I see in the program are as follows. First, you get DVD's which have Steve Demmy the founder demonstrating the lesson. If you are not comfortable teaching math or just want your child to see someone else demonstrating a lesson, this is a powerful tool. He has a lovely voice and we refer to him as the "happy man" at our house. He has a great math attitude. Second there are a limited number of problems on each page. If you have a student who is overwhelmed by math this is great. There are also many pages of practice and review in each lesson. You can review them all or stop when your student has the concept. A positive for some is that he shows many different ways to solve a problem. He is really trying to accommodate different learning styles.
In my opinion if you think this is a program you would like to try, I would borrow this program first. It is a commitment to a whole different way of thinking. Which is good, but you want to know what you are getting into.
Happy Problem solving!!