First, Kevin Barry's two collections, There Are Little Kingdoms and Dark Lies The Island. I'd have to read them both back to back to really compare, but I think I prefer the first one by a tiny margin. Anyway, they're both amazing, and though I'll endlessly hype his novel, City of Bohane, too, I do think his stories are even more outstanding. I reviewed the second one here.
Then, another Irish writer, Claire Keegan, and her collection Walk The Blue Fields. I'd heard a lot about Keegan but this is the first year I'd actually read her work, and it's fucking brilliant. If you think that Irish people writing about lonely farmers and priests in the countryside is old hat, then read Keegan at once and have a rethink. So one of my missions for 2013 is now to catch up on the rest of her books.
Finally, two that aren't standard collections (in fact, they're both marketed as novels, or novels in stories, but I'm not going to start harping on about classification and genre and structure here, because I have three years of the PhD dedicated to just that) but that are nonetheless each made up of absolutely superb stories. First, Elizabeth Strout's Olive Kitteridge. Strout's characterization is maybe the best I've ever read, and the book is funny and heartbreaking all at once, if that isn't too Hallmark a thing to say. Second, Keith Ridgways's Hawthorn & Child, a book that messes with genre conventions and ideas of closure so brilliantly I've barely shut up about it all year (review here.)
So! If you get book tokens for Christmas, I'd heartily recommend any of those. Meanwhile, I've got to go now and watch The Muppets Christmas Carol, by order of the baby. Happy National Short Story Day!