I can't say that one of the supplies needed for the cat genie tops the next because they all deserve the highest rating possible as far as I'm concerned but as far as the Washable Granules are concerned I love them for many reasons. I'm huge on saving the the environment and love the fact that the granules are made of a material that can be washed and doesn't have to be thrown out like in other litter boxes plus they help alleviate the whole strip mining issue of regular cat litter in general. The other thing I love about the Washable Granules is that you keep adding more to them and that makes it much easier on my MADDIE and me. We love our Cat Genie for her products that keep her running as well as the way she performs. Our Cat Genie has two very satisfied owners in my cat and me. We have come to consider her part of the family a very important part. Thanks again Petnovitions!!!