The best product to use for what? To protect the floor, to clean the floor, to strip the old finish off the floor?
I'm gonna presume you're looking for a finish to use on the floor.
If by "best", you mean most durable, then there are two products that come to mind, and they both use exactly the same chemistry, which is called a "catalyzed waterborne polyurethane":
STREETSHOE® 275 Waterbased Wood Floor Finish The fastest-curing finish on the market, StreetShoe® is the industry benchmark for waterbased finishes. Available in four sheens. Ideal for all commercial, sports and residential applications.
Bona Traffic - Bona
Basic Coatings "Streetshoe" and Bona's "Traffic" are both isocyanate based polyurethane prepolymer suspended in water. You mix a small bottle of catalyst into the prepolymer before spreading it on the floor. The polyurethane film it forms is several times more durable than the alkyd based polyurethanes that have been used on hardwood floors since the mid-1950's. I wouldn't be surprised to find out that both products are made by Rhodia of France, and are simply being sold by Basic Coatings and Bona under different names.
There are many different kinds of "polyurethanes". Any plastic with urethane linkages inside it is a "polyurethane", but there are hundreds of different kinds of polyurethane. The "polyurethane" that's used as oil based "varnish" or oil based hardwood floor finish is really just alkyd resins with urethane linkages inside them. An isocyanate based polyurethane (which both Streetshoe and Traffic are) has a much higher concentration of urethane linkages making for a stronger and more durable plastic.