I use Vet Solutions Aloe and Oatmeal Shampoo. It has a conditioner in it. Fiona is of a German Boxer line so her coat is kind of thick. It works great and helps to keep her soft.
The main thing I think with shampoos is that I use Frontline or K-9 Advantix on her and this shampoo is soap free, which is what you are looking for if you use one of the monthly flea topicals, especially Revolution, so that it does not strip the product.