Sur La Lune
The go-to for all your fairy tale needs, revised and source versions alike. If you have any interest in fairy tales as literature, social commentary, or art inspiration, you need to bookmark Sur La Lune immediately: it's astounding.
Short Story Collections
In the late 20th century, writers began co-opting fairy tales to talk about gender and sexuality. Seminal collections include Anne Sexton's 1971 poetry collection Transformations and Angela Carter's 1979 short story collection The Bloody Chamber.
The tradition was carried on through the 90's and into the 2000's with the 6-book short story collection series edited by Terri Windling and Ellen Datlow (starting with Snow White, Blood Red), showcasing fiction and poetry from a vast array of authors, not all of whom are known for writing fantasy. They continued their editorial work in a follow up series of collections aimed at teens (starting with The Faerie Reel).
Windling also edited a series of retellings initially published for adults (many of which have since been reprinted explicitly for a YA audience; I especially love the Renaissance England-set Snow White and Rose Red by Patricia Wrede and the Canadian urban fantasy retelling of "Jack the Giant-Killer" in which Jack is a girl, by Charles De Lint).
Trail of Tears, by Gwen Strauss, is another rich collection of retellings through poetry. Neil Gaiman's work, especially his poetry, is also rich with fairy tale themes; these and others can be found in the online archives of the Journal of Mythic Arts.
A few other collections of note:
The Rumpelstiltskin Problem, by Vivian Vande Velde: six stories that retell Rumpelstiltskin, which grew from the author's convisction that the story just didn't make any sense (just what does he want with the baby, anyway?)
For a younger audience, Vande Velde wrote a collection of fractured fairy tales, Tales from the Brothers Grimm and the Sisters Weird.
Kissing the Witch: Old Tales in New Skins, by Emma Donoghue, interconnected retellings of many of the best known fairy tales, with a lesbian twist and stunning prose.
Red as Blood: Tales from the Sisters Grimmer, by Tanith Lee, contains the most chilling version of Cinderella I've ever read; the rest of the collection is pretty impressive too. Lee tends to be ribald, bloody, spooky and odd by turns, so this one skews older.
The Rose and the Beast, by Francesca Lia Block, sets familar tales in LA, with dreamy prose and lots of teens in agony.
Want to learn more?
Fairy tale scholarship is a small but robust area, and makes for rewarding reading when you want to delve deeper (or defend your love of fairy tales when friends say they're "just for kids"). Below find a few titles that are well worth tracking down.