Only four of the best short story finalists are reviewed here. the omitted piece was to the best of my knowledge written and nominated for the sole purpose of mocking other authors and their work; as I find this contrary to the spirit of the Hugos, I'm not dignifying it with my time or consideration.
Turning to the other finalists, the cream of this otherwise stunted crop is Naomi Kritzer's short story "Cat Pictures Please,"  which was added to the ballot to replace Thomas A. Hays' withdrawn piece "The Commuter." This story was on my shortlist though it was not one of my nominations - but this was a year in which It seemed a great many superlative short stories were published. I'm very happy to see it on the list of finalists. I reviewed it earlier in the year, but I will add that I find that I keep coming back to the essential question - is it better to have full autonomy even if one screws up royally, or to live, all unknowing, under the control of a beneficent force - and pondering various aspects of it. An excellent piece of work.
S. R. Algernon's very short piece "Asymmetrical Warfare" is all about alien invasion gone wrong, from the perspective of a mission commander who makes too many assumptions based on their own culture and experience. Told as a series of journal entries by the leader of a fleet invading Earth, this wry piece (even the title is a pun) details the confusion of the star-shaped aliens as they discover that the enemy whose weapons they have been destroying are not the radiates of the ocean but the bipeds on land. Sadly, the outcome for humanity looks rather grim regardless of the misapprehensions of the invaders. A slight piece, but fun.
“Seven Kill Tiger” by Charles Shao, from the anthology There Will Be War Volume X, is a vicious little piece of work, a short shockfic with racial overtones and no subtlety - and indeed, almost no story. China, engaged in the economic colonisation of sub-Saharan Africa, finds the indigenous population unsuited to their needs - too violent, too lazy - and designs a genetic virus to annihilate all Africans. An American scientist who discovers the plan is blackmailed into silence. The end. It's a nasty scenario, proposed and then left hanging.
Thanks to the appearance of "Space Raptor Butt Invasion" on the list of Hugo finalists for Best Short Story, I have finally read something by the famed (or is that infamous?) Chuck Tingle. While I prefer my erotica to be somewhat more literary in style, I must admit that I found the story to be quite a hoot. Not sure whether I'll sample any more of Dr. Tingle's output, so to speak, but the writing was competent and the story had a good build-up, consistent characterisation, plenty of action (of the kind one would expect, of course), and a satisfying conclusion - making it a rather better effort than some other recent finalists I could mention, though not in my opinion a work of sufficient calibre to merit a Hugo award.
 my comments on "Cat Pictures Please" can be found here: http://bibliogramma.dreamwidth.org/149268.html