I really like Fresh Step. It clumps hard and I never notice an odor. With three cats, I have two boxes and scoop twice a day. I am rather a clean freak though. I may try the Prrmium that Jen mentions. Sounds like a good buy. Scoopaway is also good i think. My older cats would NOT use the Fresh Step as they got older - the smell I guess? But all three I have now love it and I love it