One of the versitile authors is John Maddox Roberts. He's done sci-fi and historical fiction and fantasy, and does all pretty well. I think my favorites are the 'SPQR' books. Mysteries set in ancient Rome, and he must have done boatloads of research, his people, places and things all ring true. There are eight of them now, I believe, with another coming out soon. And I now have all of them, he he he.
I wrote earlier about other authors I like, one I don't much care for is L. Sprague de Camp. Not a bad writer, but two things prejudiced me against him. One, he's the guy who 'edited', rewrote in some cases, Robert E. Howard's Conan stories. And two, in a collection of short stories called 'Rivers of Time'- about a man leading hunting trips into the past- he wrote enough bullcrap about firearms that it fairly permanently ticked me off. So there.