My parents were reading to me before I was even forming long-term memories. And as soon as reading lessons began in kindergarten I started reading for myself. But I can't honestly remember the first book I ever read on my own.
I will always, however, remember the first Bunnicula
book as the one that really
got me hooked on reading, at around age 6. It was the first book I stayed up late to read, and kicked off a period of my life when my parents would have to check on me to make sure I was sleeping and not reading.
Not that they minded the reading, of course (they heartily approved, really), but they didn't want me becoming sleep-deprived on account of it. Which, given my voracity for books, was a distinct possibility.