I am going to throw my 2 cents in. I am in the business and manufacture floor coatings for concrete, along with about 1400 other products for the concrete industry.
I am including a few pictures of my garage floor.
To start it all depends on what you are looking for? Showroom looks, Durability, ease of Maintenance, etc....
There are a lot of products out there, some for DYI'rs and some for Professional applications.
The DIY products are typically formulated to be easy to apply. So they compromise on the durability to do this.
Not to promote my own products, but as a car guy I formulated what I thought was the best product for garages. The product we manufacture is a PolyHydroxy compound which is designed to resist everything ( battery acid, brake fluid, Gearbox fluid etc...) basically anything that a car can leak. The product is impenetrable. So your concrete floor maintains its look without any stains, and has a glass like finish. Fluids just sit on the surface and are easily wiped up with a paper towel.
The downside is that if you get snow on it and the concrete is smooth you will end up flat on your ass pretty fast or at a minimum look like Bambi on ice. I know as I have ended up on my ass a few times.You can add silica sand to the sealer to provide abrasive anti slip so this is correctable. To get the best look, the floor should be new without any stains or oil spots, the product will cover oil stains but the finish is not perfect. Also there should not be any sealer already on the floor that would prevent the sealer from penetrating, this goes for any product.
Here are a few pictures of my floor, these are not retouched in anyway. and I have added the brochure. The product is called Durmax, it is a 2 part product, moisture cure,
The concrete itself is integrally colored Buff with highlights of Brown added during troweling.