Science fiction number one, who are they?

I am of the opinion that science fiction is the most important of all types of literature. I sincerely believe that high-quality, ingenious science fiction eventually becomes more like a part of manuals, teaching and ultimately useful literature in the practical sphere of life.

The audacity of the genre, the great demands on the author, and the very themes of the works influence society through the most productive people. So who are the most accurate and useful authors in my opinion?!

Rod Serling, Ivan Efremov and Lester del Rey!