April's recommendation: Tam Lin, by Pamela Dean, in the Fairy-Tale Series edited by Terri Windling.

I'm not entirely sure how to go about recommending this book. It's one of those that has been near and dear to my heart for ages, which means I have a hard time stepping back and articulating just why it is I love it so much. But since I do love it, I have to try.
I'll take Janet's advice, borrowed from Lewis Carroll: begin at the beginning. Tam Lin is adapted, not from a fairy tale, but from a Scottish ballad; Francis James Child included it in his enormous collection of ballads, and it's remained popular since then, to the point where a quick Google search will easily turn up some version or another of it. The ballad is kind of a feminist one; the plot, in essence, is that a young woman (usually called Janet) is told not to go to Carterhaugh/Carter Hall, so of course she does. There she meets Tam Lin and loses her virginity to him; a while later she figures out that she's pregnant, so she goes back to him and finds out that he's a mortal man in the service of the Faerie Queen and due to be tithed to Hell that night (Hallowe'en). She waits for the faeries to ride by, pulls Tam Lin off his horse, hangs on to him while he turns into an assortment of dangerous animals, and then when he suddenly becomes a burning brand she throws the both of them into water to put him out, thus winning him back from the Faerie Queen.
If you pick this book up, it will take you a while to find just where that story is in it. Your protagonist is Janet Carter -- okay, that bit's obvious -- and pretty soon a Thomas Lane shows up -- right, good so far -- and then you're four hundred pages into the book before any other bits of the ballad really manifest themselves.
This is not a book for impatient people.
It is, however, a lovely work of slipstream, or interstitial writing, or whatever term you want to use for it; I didn't think of it that way until recently, but in retrospect that's exactly what it is. Ninety percent of the book's substance is a fairly mainstream tale of Minnesota college students during the 1970s where the weirdest element is their envy-inducing ability to quote at will from English literature and drama. There are almost no signs of the fantasy plot, the first time you read through it. Subsequent re-readings have turned up hints of it here and there, but it still remains subtle; if you depend on that to keep you interested in the story, then you probably won't enjoy this much. If, however, you settle back and relax into this blurring of fantasy and fairy tale and mainstream fiction, you'll find it's a wonderful book.
For one thing, I love Pamela Dean's prose. It's not fancy, aside from the liberal quotations taken from the literature of the ages; if you'd like those glossed, the Annotated Dean webpage is very handy. You can easily come away with a list of things you Really Ought To Read, like The Revenger's Tragedy and The Lady's Not for Burning. But even when Dean isn't quoting, there's just something elegant about her writing, I think; it's friendly and accessible, and yet finds ways of articulating things I never would have thought up on my own. There's humour in here -- a lot of it -- and also conflict, and the occasional, electric hint of Something Strange. One of my favorite quotes comes when the ballad plot has finally leapt onstage, and Thomas is discussing his probable fate:
"I don't want to die, but it's a thing people do. But I should be dying for some human thing, even if it's folly or stupidity -- not for her. Not for them. They're not evil; even that is comprehensible; people can be evil. They're foreign. They're like Linear A. They look as if they ought to mean something, but you can't tell what it is."Dean does an excellent job of bringing strangeness into the mundane world so that it seems utterly real without losing its magical qualities. Making the Queen of Faerie a professor in the Classics Department does not rob her of her grandeur, because she still carries that sense of Other. When she doesn't -- when she comes down to earth, seems ordinary, like a professor you might once have had -- it's because she's putting on a mask. And when the mask isn't there . . . well, many fantasy authors should wish to be so good at conveying the essence of Faerie.
Look, I successfully recommended something that is totally a stand-alone book! <g> There are other books in the Fairy Tale series, and some of them are very good; I might recommend one of them someday. Pamela Dean has also written other things; unfortunately, the only one you're likely to be able to find is Juniper, Gentian, and Rosemary, based very loosely on the traditional song "Riddles Wisely Expounded." Her earlier books -- The Dubious Hills, and the trilogy The Secret Country, The Hidden Land, and The Whim of the Dragon -- are wonderful in their own right, AND (an update from what I originally said), they're going to be reprinted soon. So, if you read Tam Lin and like it, you might want to keep an eye out for them..