What's your favorite litter?

I've been doing a lot of litter box duty for the last few months, and I have come up with a recipe for a mixture of cat litters that I like. The rule for number of litter boxes is "one for each cat PLUS one", so for my brother's 40 cats, we would have needed 41 boxes. That wouldn't have left much room in his home for walking around, so he only had about 6 boxes - one being a large bin. When you have a lot of cats using only a few boxes, clay litter can get H*A*R*D pretty fast. I added a couple of boxes, but decided that I needed to try other litters. I like World's Best litter (corn based), but it is expensive, and at first I thought that it would cost too much to use for such a large group. Since I've found that it can be used longer than clay, I decided to give it a try, and found that the expense was not as high since I didn't need to refill it as often. Then I decided to add some Nature's Miracle litter to see if it would further reduce the odor after many uses. I really liked the fluffiness that the Nature's Miracle added, and believe it is a really good combination -- the corn granules form nice tight balls around the urine, while the fluffiness of the Nature's Miracle helps make the scooping easier (no cement blocks to try to dig thru) as well as keeping any messes from sticking to the sides of the box.