I have been using Arm & Hammer's Super Scoop and so far I like it the best. It has been the easiest to clean with no odors and Rascal doesn't get it all over the place. He is a digger and a flinger - so I only put about an inch and a half in the litter box. It seems to stay in the box and not get all over the floor.

I had not heard of "World's Best", but I recently heard about a type of litter that is made out of wheat. It is flushable. Friends live on the third floor of a condo complex and they have to take the trash to the first floor - so they were happy to not have to lug used cat litter down three floors.