As far as I know, Clarisonic does not sell anything actually labeled as a "moisturizer." They do sell two serums, though--one is for use with their Opal, and the other is Dr. Robb's renewal serum, which can be used "alone or with a moisturizer." If your skin is dry, you would probably need to use a moisturizer over either of these serums. I have found that, after using my Clarisonic, I need to use more moisturizer because it absorbs so well and so quickly.
But the idea behind the Clarisonic is that it cleans your skin so well that it allows whatever other products you use to absorb better and, therefore, to work better--and I believe that it does. As far as moisturizers, it depends on whether you are looking to just moisturize or are looking for anti-aging stuff. I use products by SkinMedica that I think are very good. Specifically for a moisturizer I use Dermal Repair Cream at night and their lightweight moisturizer for day. I also like M.D. Forte Replenish Hydrating Cream (without glycolic acid). The MD Forte is for sensitive skin, unscented, is very gentle, and does a great job of softening skin overnight. I also like Estee Lauder moisturizers. There are so many different kinds of moisturizers on the market, though, it is a good idea to get samples and try them first if you can. If you live near a Sephora, they are usually happy to give you samples of stuff to "try before you buy." Sometimes department stores will give you samples, too. You just have to ask.