Is there a good shampoo or method to getting my dogs coats healthy and shiny?

I have a medium length haired Shepherd and her coat seems healthy but has been looking pretty dull lately and I would like to pep it up. I've tried some cheaper dog shampoos but they never seem to really work.

My maternal grandparents used to breed German Shepards. They always used Milk and an egg together for the beautiful and shiny coats. BUT as we have learned, it is not good to give your pets milk, so maybe you can substitute goats milk for the cows milk.

We use a fish oil supplement in our dog's water bowls to keep their coats shiny and healthy.