The short fiction category in particular is easily digestible - only four stories on it this year, and all are now available online. I thought they were all very good - even "Arrhythmia", which I did not find especially adventurous, is at least very well written - and recommend them all. In reverse order, my votes will be for:
4) "Arrhythmia" by Neil Williamson (PDF)
A grim dystopian tale of an industrialized small-minded society, and an illusory spark of youthful rebellion through music. Somehow very English in the way it is told, though the factory environment reminded me most of Zamyatin (who apparently was using contemporary England as his model for We). Very nicely done, though one has a good idea from the start of where it is likely to end up, and it's really the kind of story Brian Aldiss might have been scornful of fifty years ago.
3) "The Shipmaker" by Aliette de Bodard (PDF)
This is a rather lyrical tale setting in close juxtaposition the creation of a spaceship and the birth of a its future pilot. I wasn't always quite sure what was going on, and I suspect I missed some of the context by not being familiar with de Bodard's Xuya sequence of stories in which China discovered America before Columbus, but I loved reading it.
2) "Flying in the Face of God" by Nina Allan (PDF)
Like Williamson's story, somehow very British in tone: a journalist explores the effects of spaceflight (and interrogates the reality of memory) through both her friend, who is being gradually mutated by a new treatment for astronauts, and her mother, who was killed many years before when her mission was sabotaged on take-off. There is lots of stuff here in such a short story and it is juggled very well. (I wasn't quite sure about the timing of some of the biographical details of the protagonist's mother, but I guess good stories are often told about unusual people.)
Interesting to note that both the de Bodard and Allan stories are by women, about women, set in an alternate history where space flight developed differently from our reality, and published in Interzone. Maybe I will start subscribing again.
1) "The Things" by Peter Watts
An excellent atmospheric re-telling of The Thing from the Thing's point of view. I haven't seen either the 1951 or the 1982 films, but I have read the original story, Who Goes There? by John W. Campbell jr, sufficiently long ago that I was hazy on the names of the characters (which are from the film here, rather than the original story) but still familiar with the scenario of the shape-shifting alien entity taking over the scientists (and dogs) on an Antarctic base, one by one. I thoroughly enjoyed it; Watts is disturbingly convincing at conveying the alien entity's disgust with humanity, and its own efforts to work out what is actually going on make an effective counterpoint to the efforts of the humans to defeat it.
With some hesitation, because I liked all the others, particularly Nina Allan's story (which I note has the support of Williamson and de Bodard!), "The Things" gets my top vote.
And I must say I'm impressed by the tastes of the BSFA selectorate. I haven't read much short SF in recent years - reading big heavy books has biased my mental gears towards the long form, though I do try and at least what has been shortlisted for the major awards. But unlike last year's list, where I found three of the six stories awful (including the winner), and unlike the Hugo nomination lists, which occasionally make me despair, I actually get the feeling from this rather short shortlist that I may be missing out by not reading more widely.