Wow, this thread really brought back some amazing memories! I grew up with a huge, and I mean huge library at home. My grandfather started the collection and my mom carried on the tradition. Their tastes, and therefore mine, were eclectic.
I started reading 'adult' books when I was twelve. Never had any problem getting my hands on anything I wanted to read... it was all right there; although my mum did make it very clear that Harold Robbins was a no-no!
Lets see, there was Exodus, Trinity and QB-VII. Some War and Peace and Crime and Punishment (and no, my life is depressing enough as it is, I'm not going to re-read those!). I loved anything I read by Steinbeck. Liked Allen Drury, Pearl Buck, James Hilton.. oh and To Kill A Mockingbird, one of my childhood favourites and one that I've re-read several times. Oh and not to mention the mystery stories a la Agatha Christie, Ngaio Marsh, Dorothy Sayers and P D James. There was also a decent amount of Asimov and Arthur C Clarke. Missed Michener.
I also have to admit that my mum had more than 450 Mills & Boons (her collection started when she was living in England in the early 70's) and I've read the whole lot!
Right now I'm going through the 'Urban Fantasy' genre; presently reading the Allison Beckstrom series by Devon Monk and bought Divergent (Veronica Roth) to read next.