Okay, time for the "big one." (No, not novels. I barely read any novels released in 2015 and of those few I'd only recommend one, so no post for them.) If you haven't already, here are my posts about novelettes and novellas. And I'd be remiss to not point out that I have an awards eligibility post please read it please love me. Anyway, on to the stories!
This category always has the most things to consider, so even more than any other category, this is just basically "stuff I really liked/stayed with me" rather than "the best." I also tried to pick stories that I think have been more overlooked than others, not that there aren't good reasons for some stories to go viral, but I prefer to signal boost more obscure work. (And I still wish there was a flash category in Nebulas/Hugos. There's SO MUCH flash being published now, but flash would have a hell of a hard time getting nominated. It's different enough from short stories that I think there's a need for the category. But that's a post for another time, or more likely, never.) Nine stories, online links where available:
"...And I Show You How Deep the Rabbit Hole Goes" by Scott Alexander (Slate Star Codex): Technically not a story published in a science fiction magazine, but a blog post. But it's fictional, so it counts. Eight second-person narrators each take a pill that gives a different superpower: shape-shifting, control over machines, seeing into the future. What starts out as a light, funny romp in the first act becomes a deeply philosophical story about determinism, as the eight (well, uh, seven) come together to reverse entropy. The epilogue brings it back around to humor, as Alexander reminds us of the true power of BRUTE STRENGTH.
"Duller's Peace" by Jason Sanford (Asimov's Science Fiction): Totalitarianism and paranoia. A near-future government has devised motes which read citizens' thoughts, in order to weed out subversive elements. Our protagonist is Serija, a young girl whose mother dies in the first few paragraphs due to a stray revolutionary thought. This story makes really good use of a child protagonist, as we learn the true depths of the nation's crimes against its citizens as she does, in real time. The titular "peace" brought about by the motes is a clear allegory for social media, and Sanford skillfully portrays the futility of fighting against an enemy that can reach into your mind -- though there is a revolution of sorts here, there is no hope of permanence. Very dark and very good.
"Egg Island" by Karen Heuler (Clarkesworld): People with plastic prosthetic devices better than the real thing congregate on an island itself created out of plastic, and discuss the evolution triggered by mankind's wasteful behavior. Heuler's simple prose implies a mystic bond between these partially synthetic humans and the new ecosystem (inspired no doubt by the Pacific Garbage Patch). This is probably the most positive story I'm highlighting, and of course, one can wonder if the eventual replacement of organic life with synthetic life is wholly positive. But it certainly is for these hybrid people witnessing the dawn of a new era.
"Here Is My Thinking on a Situation That Affects Us All" by Rahul Kanakia (Lightspeed): A spaceship that has lived within the Earth's surface for billions of years rises above New York City, a momentary stop before fulfilling its mission of harvesting the energy from our gas giants for the small benefit (very small) of its "creators." The voice is what really makes this one, as the deadpan, childlike tone of the spaceship (which uses words like "oozy" and "gloopy") belies the cosmic indifference of both the spaceship and the creators toward humanity. A love story of sorts develops between the spaceship and a human ambassador, though considering the circumstances, it's pretty one-sided.
"It Is Healing, It Is Never Whole" by Sunny Moraine (Apex): In a nebulous world not quite life or death, an unnamed narrator collects the souls of suicides in order to load them onto an infinite train. But one soul is different: it has eyes, and the narrator forms a bond with it, one that leads to a profound meditation on what it is that causes the suicidal souls to give up on life, calling it a "lethal temporal failure of the imagination." As someone with a personal connection with the subject matter, I found it incredibly moving and wonderful and true. This is a story that rewards multiple re-readings.
"Noise Pollution" by Alison Wilgus (Strange Horizons): If there's one thing I never quite get sick of, it's stories narrated by possibly-crazy people who might be fighting a real enemy but might not be, and no matter what the real story is, they're still a little fucked up. (I think this sentence describes approximately 75% of my own stories.) This is an awesome example of that thing I just said: a narrator fighting against the titular Noise, armed with only a Walkman and some old tapes. Just a really fun romp of a story, with a great voice (or is that Voice?).
"Prototype" by Sarah Langan (The End Has Come): More freakin' dark SF. This is technically the third story in a series of shorts spread out over three collections, but can be read as a standalone (although the other two are quite good as well, and flesh out the backstory). A post-asteroid-strike future shows the surface of the planet being inhabited by caretaker cyborgs, who fashion suits to protect their human brains from unceasing sandstorms. The protagonist sets out to save his dying dog, taking the reader on a tour of this completely changed world, and only in the last few pages do we discover the bleak truth about the relationship between cyborgs and organic humans. (Spoiler alert: it's not a dog.)
"Serein" by Cat Hellisen (Shimmer): When Alison's sister Claire disappears, her whereabouts are a mystery: no body, no plane ticket, presumed dead. But Claire is still here, having dissolved herself into water and mist, and continues to haunt the spaces around her family. The images in this prose poem stuck with me for a long time, and the seamless POV switches between the two sisters show two sides of a bond broken by this strange magic. Lovely work.
"This Is the Way the Universe Ends: With a Bang" by Brian Dolton (The Magazine of Fantasy & Science Fiction): In a far-distant, post-human universe, an entity known as Titus navigates the complicated politics of several factions committed to destroying, leaving, or awaiting the death of the cosmos. This piece reads like poetry in places, its sweeping prose guiding us through a grand tale of intrigue and war. Though the mystery is easily decoded, I was enraptured by Dolton's storytelling itself, and by the story's melancholy end.
And that's it! Vote early, vote often, read always.