Have a cat (or more than one)? If you like Fresh Step litter, then go to their website and join the Paw Points club. Every time you buy their litter, you get a code off the package and enter it to earn rewards. Up until the end of September, the 20-lb boxes---which normally are worth 50 points---get double the point value.
I have tried several different litters, most infamously a huge bag of litter from a pet store for under $4.00. It was so big I could hardly lift it, and it lasted forever. That was unfortunate, because it was the absolute worst litter I have ever used. It not only didn't clump, it didn't help with odor control. I am not kidding, you about needed a gas mask to approach that litter box---and I clean it on a regular basis.
Fresh Step so far has worked the best for us (one of my cats has tummy issues so ODOR can be a real problem). If you use it, sign up for the club and earn points. I'm collecting points to earn a free bag of litter.