Some good concrete sealer products include Brickform, V-Seal and Kingdom Products. The best concrete sealer depends on the type and location of the concrete and other varying factors such as the desired finish.
For any concrete sealer, the product's performance is largely determined by the application surface. MasonrySaver Decorative Concrete Sealer is a highly-rated product for properly cured, stamped concrete applications. Surebond SB4000 is the best for concrete, retaining walls and pavers. MasonrySaver Heavy Duty Water Repellant Sealer is ideal for horizontal and vertical above grade surfaces. SuperSeal M Concrete Water Repellent is a highly-rated, clear waterproofing sealer for porous surfaces.
All of these sealers have been rated 8+ out of a possible 10, according to Concrete Sealer Review. Before committing to a particular concrete sealer, consider the desired application, cost, finish and maintenance of the product.