This is one of those books that goes against my general rule about the attractiveness of the cover predicting the merit of the novel, since it's a cover I loathe but a novel that I love. Ella Enchanted by Gail Carson Levine is one of the first books that I consciously remember reading and adoring from page one. I first picked it up in the fourth grade and can still devour it in one sitting ten years later, which is a clear indication that it has something big going for it.
Ella Enchanted is a brilliant fractured fairytale version of Cinderella (duh), which takes the basic Cinderella story and weaves in all the other exciting elements of fairytale lore that the traditional take lacks--adventure, mystical creatures, dastardly plots, true romance, and a protagonist with a real personality, among other things. Out of all the Grimm or Disney Princesses, the one I've always hated on the most is Cinderella because she actually doesn't do anything. She plays second fiddle in her own story, and that's just sad. Levine's Ella takes the reins and works hard to steer a life that is very much out of her own control.
The story is very much like the original fairytale in a lot of ways. There's the distant father, the dead mom, the evil stepmother and stepsisters, the handsome prince, and the fairy godmother...and then there's a curse that forces Ella to always obey any order given to her (see the danger there?). The curse, really, is the most interesting part because that's where the deviation from the original story comes from. It's what gives Ella much of her spunk and appeal as a character. She lives her life under this unwilling compulsion to always do as she's told and is always doing her best to fight it, which gives her strength as a protagonist. Beyond that, she's written to be witty and brave and commanding, and these are all traits that the traditional Cinderella clearly lacks (actually, the only real personality trait that the original Cinerella has is "whiny". Lame).
The plot's the part I just can't give away. It's much too much fun, so you should discover it for yourself. If you're a fan of fairytales and, of course, strong female protagonists, you'll love this book, and you'll have just as much fun with it whether you're five or fifty. I always throw Ella Enchanted at pre-teen girls, but the best thing about it is the fact that it's really appropriate for anyone at all.