It is recommended to use either a penetrating sealer or an epoxy system on a garage floor. A penetrating sealer like the Siloxa-Tek 8505 or the Siloxa-Tek 8510 is best if you are looking for natural finish. The major difference between the two products is that the Siloxa-tek 8505 is water based and the Siloxa-Tek 8510 is solvent based. The Siloxa-Tek products will resist degradating deicing salt damages to reduce cracking and spalling and they will resist exposure to grease and oils.
If you are looking for more of a coating or decorative finish a better choice would be an epoxy system. An epoxy system consists of an epoxy basecoat like Epoxy Max 100 and a topcoat like the Armor-Tek 830. However, if you want to get really into it and make concrete sealing fun, you can add decorative paint chips or metallic pigments with the Epoxy Max 100 for a high build decorative garage floor. The Polyaspartic 930 is an excellent topcoat for flake floors and the Armor-Tek 830 is an excellent topcoat for metallic floors. Penetrating sealers and epoxy systems are popular concrete sealers for a garage.