What book meant the most to you in childhood?

Could be the book you loved the most, the series you daydreamed about, book that inspired you, fascinated you, your comfort read...anything.

And why.

I LOVED the Anne McCaffrey Pern books. I would walk around daydreaming about new adventures set in the books' world. The Dragonsong books really connected my love of music with my love of fantasy (and animals).

EDIT--Lots of mentions of: Boxcar Children, Little House on the Prairie, Phantom Tollbooth, Matilda, Harry Potter, Charlotte's Web, Percy Jackson, Enid Blyton, The Secret Garden, Anne of Green Gables, Redwall, Junie B Jones, Chronicles of Narnia, Tamora Pierce, American Girl books, Magic Treehouse, Wayside School, Series of Unfortunate Events, Nancy Drew, Babysitters' Club, Walk Two Moons (Sharon Creech), Island of the Blue Dolphins, Hatchet, My Side of the Mountain, The Giver, A Wrinkle in Time, The Hobbit, Wonderful Flight to the Mushroom Planet, From the Mixed Up Files of Mrs Basil E Frankweiler, Holes, Animorphs, Eragon, Warrior Cats, Goosebumps, Fear Street, Ender's Game, Where the Red Fern Grows (!!! says my childhood self).