5. The Dark Is Rising Sequence by Susan Cooper
4. The Graveyard Book by Neil Gaiman
1. Harry Potter and the Philosopher's Stone by JK Rowling
It is hard to talk about this book in isolation from the rest of the series. Like many others of my age, I grew up with Harry Potter - literally. Initially, I began reading the books out of sequence; I picked up The Prisoner of Azkaban at the age of thirteen, the exact same age as Harry in the book. After that, I read The Chamber of Secrets, which I found lightweight and disappointing (it is by far my least favourite of the entire series). When I finally got around to reading the first novel, The Philosopher's Stone, I was under the impression that reading about eleven-year-old Potter's adventures would be fluffy and easy compared to the dark twists and turns of The Prisoner of Azkaban. I was pleasantly surprised; the first book does the incredible job of creating the mythology of Rowling's wizard world with remarkable ease, as well as setting the young hero on his path from the very first chapter where he miraculously survives the death of his parents. It doesn't get much darker than a double murder, not to mention the Roald Dahl-esque abomination of a family with which Harry endures his early childhood. From the outset, Harry is an underdog, an everyman. A hero with no outstanding personality traits, which meant that young boys could imprint their own personalities onto him, inserting themselves into the starring role. After the third book in the series, events began to take epic, tragic turns. Classmates are murdered, Voldemort's power grows, the delicate balance between the wizarding world and that of the muggles begins to blur... but it all begins with a baby on a doorstep in the suburbs.
Another trilogy by Robin Jarvis which I very nearly included in this list is The Whitby Witches, about a pair of orphaned siblings who are fostered by an elderly eccentric named Alice. The youngest of the two, Ben, is cursed with second sight, a power that is greatly coveted by many in the small seaside town of Whitby. I would also highly recommend Tolkien's The Hobbit and The Complete Works of Saki.