This is what I recommend:
http://www.ashfordformula.com/
It is a sealer/surface hardener, easy to apply, becomes one with the concrete so it will never peel up or scratch. It prevents dust, resists all but the most harsh fluids, and really does get better looking with age. I like the look of a well done concrete floor (I have been a finisher for 25+ years) and with this stuff, it looks like there is nothing on the floor, until you have a spill, then whatever it is-it just wipes up without staining. It is the best stuff I have come across. Ashford is a brand name, I'm sure there are others, but any concrete supply house will know of it.