for the residential we use Minwax urethane hardwood floor finish, usually a clearn semi-gloss unless someone wants it shinier, in which case we'd use the gym floor finish. We also mix it up with a product called ProFloor finish which is about $10/gallon cheaper and works just as well.
The gym floors are getting a bona fide "gym floor" finish, at least that's what it says on the can. It's a polyurethane as well, but it's what I consider to be a super high gloss. It dries shinier than anything you can buy off the shelf. I'm fairly certain that it has a higher VOC content than what you can buy over the counter as well. I know we have to "import" it from Kentucky because Ohio won't sell it with the VOC content being what it is.
Sooner or later we're gonna have to move to the water-based finish that all the big boys are using. It's not nearly as good, as is the case with all the things they're outlawing now (asbestos products, lead-based paint and things like that) and the water-based just doesn't look nearly as nice. Those old timers with their asbestos shingles, lead-based paints and urethane finishes sure knew how to make products that last a lifetime.