Category One: Space-based.
(ex// an alternate universe directly involving space or space travel)
The Martian Chronicles (Ray Bradbury)
The Sparrow (Mary Doria Russell)
The Gods Themselves (Isaac Asimov)
WINNER: The Sparrow (Mary Doria Russell)
Category Two: Not space-based.
(ex// an alternate universe not directly involving space or space travel)
Never Let Me Go (Kazuo Ishiguro)
A Scanner Darkly (Philip K. Dick)
The Road (Cormac McCarthy)
1984 (George Orwell)
Fahrenheit 451 (Ray Bradbury)
WINNER: The Road (Cormac McCarthy)
OVERALL WINNER: The Sparrow (Mary Doria Russell)