Geez, off the top of my head? ( Gears grinding, ears smoking from effort of thinking... )
The Weapons Shop of Isher ( novel & short-story versions exist ) by A.E. Van Vogt-
Most anything from Phil K. Dick, Roger Zelazny, Michael Moorcock, John D. McDonald...
Jerry Ahern's Survivalist series had its moments-
Grew up on ERB's Tarzan & Mars series, ditto Sax Rhomer's Fu Manchu--
Fred Saberhagen's Love Conquers All changed my mind about abortion, with a little help from PKD's The Pre-Persons...
The Twilight Men, by Otto Basil- how Hitler nuked NYC, won the war, and the collapse later of the Nazi regime...
Whoops- wife ( the Queen ) and dog ( the Princess ) are giving me dirty looks again- gotta run...
Probably my favorite writer.