Three of the most prominent authors of the supposed "Golden Age of Science Fiction" were Isaac Asimov, Robert A. Heinlein, and Arthur C. Clarke. In fact, they are often listed as the "three greatest practitioners of science fiction ever." These authors seemed to typify the ideals of SF at this time. There was a lot of scientific extrapolation with a generally well written story, but lacking in any depth of characterization or (usually) any literary insight (although it was a far cry above the usual pulp material of Hugo Gernsback fame). Stories from these authors were typical of these Golden Age ideals, but vary a good deal in quality.
Isaac Asimov's name is to many people synonomous with science fiction, but I believe he is the inferior of both Heinlein and Clarke. At his best, he writes what we could call quality SF (compared to the Ray Guns and Rocket Ships of earlier days, anyway) that is indeed very thoughtful and inventive, but doesn't stand up to the standards of literature in general; and if SF is to be taken seriously it must be able to meet these standards at least as often as any other genre. In some of his lesser work, though, Asimov doesn't even live up to the standards of the genre itself. He breaks the conventions that have developed over the years into certain "rules of the genre." For example, you don't have a character say to another character "Well, of course you know that..." and then go on to explain some well known aspect of their society. People of today don't say to each other "Well, of course you know you must drink water everyday to stay alive." Of course we know that! Why should we need to explain it to each other? But Asimov often tells his stories in such an implausible manner. He has entire dialogues with the characters lecturing each other on elementary (in their society) facts. Other than this, his strengths are often his downfalls. Although his prose is the essence of clarity, it is also consequently transparent and lacking in any inventiveness.
Robert Heinlein and Arthur Clarke have reputations just as big, if not bigger, than Asimov within SF circles, but in this case they are, I believe, more deserved. They don't seem to make the elementary mistakes that Asimov does, and they have more as far as individual merits. Clarke is the undisputed master at evoking that childlike sense of wonder (witness "The Sentinel") while Heinlein had great diversity and often wrote about social and political concerns. Asimov may have occasionally done these things to, but to a much lesser degree.
All three of these authors, despite their differences in style and quality, were definitive of Golden Age SF. They were all very knowledgeable in science and could , to a certain degree, spin a good yarn.