There's an interesting little article in the Guardian today, that asks the question--"What fictional school would you like to go to?" I'm an inveterate reader of English girls' boarding school books, despite the fact that I would utterly loathe the vast majority of the schools-- so much organization of one's time, so little chance to creep off alone with a book, so many long organized walks, cold baths, and compulsory games. There's one book, in fact, (Lucy Brown's School Days, by Dorothy Vicary, 1951), whose plot revolves on the rehabilitation of Lucy from a book reading, chocolate-eating introvert to a star athlete and all round team player. Horrors. Even the fact that many of these fictional boarding schools have great settings, such as Mallory Towers (Enid Blyton), a castle-like structure on the coast of Cornwall, I'm not convinced it would be worth it.
One school that breaks from the pattern is Josephine Elder's Farm School, which she wrote about in three books: Exile for Annis (1938), The Cherry Tree Perch (1939), and Strangers at the Farm School (1940). This is a rather utopian school, where you get to pick the direction of your own studies, all the while learning practical skills and helping to look after the farm. And the students are so busy actually doing their own projects at their own pace, and doing communal work, that they are never organized for Walks. So this is my pick for fictional school.*
Copies of the Farm School books are fairly common and inexpensive, but sadly most of these are the Children's Press Editions. Children's Press books are often, but not always, horribly abridged. I've never read the non-Children's Press editions of these myself, but it's my understanding that Exile for Annis survived pretty much intact, but the later two got damaged.
Sort of straying off the topic of fictional schools, I'd just like to say that The Best Girls School Story Ever is Evelyn Finds Herself, also by Josephine Elder. Which really deserves a post to itself one of these days.
*Hogwarts, fun though it is to read about, would be very frustrating to attend. Not just because of titanic struggles against evil and that sort of thing, but because of the inconveniences of the stairways and passwords and all, and the lack of a decent education. (And thinking about reading at school, does any student ever read any fiction for fun?)