Every house has a kitchen and every kitchen usually has countertops. Granite and Formica are commonly used countertop compositions. Concrete countertops on the other hand are newer, making a rise being cost effective and aesthetically pleasing. Since concrete is so porous and since concrete countertops need to be protected from water, and household acidic substances, sealing them should be a priority.
The best type of countertop sealer is a topical yet penetrating solution. You want to protect the full thickness of the counter and especially the top of the counter from wear and use. You want to make sure you use a sealer that is specifically designed for use on countertops. I would try to stay away from a company who is claiming their floor or wall sealer will be effective on countertops. Look for a manufacturer who specialized in concrete countertop sealers.
Epoxies and urethanes can be used on a countertop in conjunction with metallic sand or decorative paint chips, yet we have found this process to be time consuming. However if this is the type of finish you are looking for epoxy and urethanes especially designed for countertops are the way to go.
If you are looking for a natural finish, the penetrating topical solution will be your best bet. Used in conjunction with a concrete wax, applied regularly, a shine rivaling granite countertops is achieved.