Okay, I cheat. It's a tie. I absolutely adored Emily of New Moon, the lesser known precocious orphan creation of Lucy Maud Montgomery. Black haired and black eyed Emily is a writer, which I always fancied myself to be, whose imagination runs wild. Add in the unbelievable idyll that is New Moon farm and childhood love Teddy, and... sigh. Escapism. I read it to my girls last year and they loved Emily as much as me.
A close tie is the Arabian Nights' Entertainments, illustrated by Dalziel, I think... though I suspect the edition I had was a mash up of pre-raphaelite woodcuts. They were transporting. I adored reading the strange stories and losing myself in the bizarre and beautiful world of the pictures. This is the one book I heartily regret not holding onto into adulthood.
-- Posted from my iPhone