3) "Mantis Wives" by Kij Johnson. This is an interesting idea, but it isn't actually a story.
2) "Immersion" by Aliette de Bodard. Nice style but didn't engage me.
1) "Mono no Aware" by Ken Liu. Superb stuff, updating "The Cold Equations" with a huge dollop of cultural awareness. No doubt experts will whine that the engineering in the story is unsound, but it convinces me enough for the emotional impact.
I feel much more strongly about this ranking than any of the other three fiction categories.
See also: Best Novel | Best Novella | Best Novelette | Best Dramatic Presentation (Short Form)