Oscar Wilde, The Picture of Dorian Gray (1890)
I remember well finding the premise of this book absolutely terrifying when one or the other of my parents described it to me when I was small. I was certainly not disposed to read it, although even if I had tried such a thing back in the day, I would quite definitely have gotten bored and quit before the picture itself becomes a thing. Probably before Dorian himself even appears, actually. Now, however, I'm less likely to be bored and/or scared by books (except RA Salvatore books--there, it's kinda the opposite), and I had two additional reasons to check it off the list: a friend recommended it, and there was a brief excerpt from it in a lesson I recently taught which made me think, huh. That looks kinda cool. SO THERE YOU GO.