Spider Robinson: not SF? The Callahan stuff? The "Dancer" stuff he's written with his wife? Mindkiller? His Hugo?

Dana Stabenow: better known for mysteries, for which she's won an Edgar. But her first novels were science fiction, and she wants to get back to it.

Pat Frank: wrote Alas, Babylon, one of those post-nuclear-war novels.

And how about

Cordwainer Smith
Edgar Pangborn
Harry Turtledove
Anne McCaffery
Madeline L'Engle

and even

Kurt Vonnegut.