Let's take a look at these three possibilities:
1. If dampness is your issue, or you are concerned about future staining, the best way to start work on your garage floor is with an internal concrete sealer. This is done by simply wetting the floor down with the concrete sealer. Most internal concrete sealer products leave nothing on the surface of the cement, because it works internally inside of the cement. The goal of using such a product is to seal and water poof your garage floor, but does not fill cracks etc. So, if this is your goal then this is not the right product for you. Normally you will not even know you have applied the product; however, by applying the product you have protected the surface of your garage floor; this means that stains, oils, water, etc. are less likely to flow into or out of the cement. The advantage of making your garage floor water proof is that it is a quick, easy, inexpensive way to protect the cement without closing down any future options such as later staining it, etc.
2. For a functional working floor use a water based floor epoxy. Water based epoxies offer an alternative to regular epoxies: One a water based epoxy will generally act as both a primer and finish coat. Most water based epoxies come in a light gray color, and look for one that says it will not yellow. Also, look for a water based floor epoxy that offers good coverage, this will save you time and money because you may not have to go over your floor more than once. Water based floor epoxies, being water based, soak into the floor a bit, which provides a superior bond and less likelihood of coating failure, thus it can be a good primer coat or a finished topcoat. Look for signs of trouble as you apply it, for example, if the epoxy beads up during application you likely have wax or oil or something on the floor to which the epoxy won't stick.
3. If you want a showroom look for your garage floor, then you will want to do the following: For a glossy, thick, glazed tile look, you will need to use a solvent free industrial floor epoxy. It should go over a concrete sealer and or waterbased floor epoxy, or over any well adhered floor paint. If the paint is not adhered well, ten you will have problems with your solvent free epoxy. Also, after all the work to make your floor look like a showrrom, you do not want to mess it up because of neglect. Protect your epoxy floor. Epoxies will yellow in direct sunlight so to protect them from UV yellowing by covering garage windows, also keep them shiny, and more scratch resistant, by using a topcoat with the epoxy or epoxy chip floor with our two part acrylic polyurthane with UV blockers.
Garage floors can serve many functions, so find the garage floor covering that works for you, prep your floor well, and enjoy.