Easy. Reading in general. Christopher Pike's fall into darkness. I discovered his realistic suspense back in the fifth grade and believe me those books were meant for teens. Not kids that young. However, a lot of the adult references went over my head and I just loved the stories.
Romance...my first romance (besides Twilight) was Jay Mclean's More Than This and OMG yall I was hooked. The pain. The spice. The love. **chef's kiss** If you haven't read it I highly recommend it.
What about you? What book sparked your love of reading?