I've heard a lot of people wondering what they'll do post-Potter, as they now have NO EPIC SERIES FANTASIES TO READ.
I like teen fantasy novels better than almost anything else in the world, so these are my suggestions (though you've probably read most of them)…
Susan Cooper’s The Dark is Rising series, the Grey King being my very favorite and perfectly good as a stand-alone. Plus, they’re making a movie out of the first book and you really ought to read the book beforehand so you can smugly point out that "the book was soooo much better."
Lloyd Alexander’s Prydain Chronicles
Ursula LeGuin’s Earthsea series - don’t be put off by the crappy miniseries they made a few years ago, the books are gorgeous. I’m particularly fond of these because I had a book-on-record of The Tombs of Atuan when I was a kid and used to listen to it every night before I went to bed. I realize this means I was a dark and strange child, but I’m comfortable with that.
Madeleine L’Engle’s A Wrinkle in Time.
The Abhorsen trilogy, by Garth Nix: evil spirits, flesh-hungry ghouls, kick-ass ladies, and a talking dog. What more could you want? Bonus - the heroine of the second novel is a librarian.
Robin McKinley’s Beauty
Ann McCaffrey’s Dragonriders of Pern series
Anything Tamora Pierce ever wrote, though my favorites are the original Lioness books, starting with Alanna: the First Adventure, in which a girl pretends to be a boy so she can be a knight, and much ass-whooping, sorcerous shenanigans and romantic entanglements ensue.
Annette Curtis Klause’s Blood and Chocolate: yes, the book is much better than the movie.
Diane Duane’s Deep Wizardry
Darren Shan’s Demonata : seriously gruesome, but a damn good read, from an author much-beloved by teenage boys.
While these are technically “grown-up” books, and I don’t normally hold with that sort of thing, I can still recommend the David Eddings Belgariad and Mallorean as funny, epic and, while not hugely original, still highly entertaining. Also, Marion Zimmer Bradley’s Mists of Avalon (a feminist retelling of the King Arthur legend), and Kelley Armstrong’s Bitten (an excellent and original revision of werewolf mythology, plus, it’s got plenty of smutty bits).
So what are you reading post-Potter?