Rustoleum makes an excellent product for garage floors. It isn't epoxy, but it holds up and cleans up well. The most important thing is to prep the floor first. You need to get the oil and grease up as much as you can with simple green or something and a stiff brush. Rinse it well, then let it dry. After that you need a 50/50 solution of Muriatic acid (pool acid) and water. Use a garden sprayer and spray the floor good. Keep the doors open because this stuff smells bad. Let it do it's work for a few minutes, it will foam and turn green. Rinse it well again. This will etch the concrete and give the paint something to grab on to. Let that dry, then paint over it and you are done.
That's a lot of work. So, I will do it on a weekend. Thanks