I don't think it comes down solely to the designer, instead think of the company and team of professionals who make a great UI possible. A great UI design trapp

I don't think it comes down solely to the designer, instead think of the company and team of professionals who make a great UI possible. A great UI design trapped inside of a photoshop file is useless. It takes the effort of multiple people to make it happen - I think a better question to ask is what companies are creating the best UI's that are actually being used today.