Brit - I'm going to break hearts go against the grain again and say that Crimson Petal and the White started out promising and well-written but then descended into 1000+ pages of pointless drivel about domestic boredom. If it had any point at all, it may have been that even the most interesting & amazing woman you can imagine (like an intellectual prostitute in Victorian London) will get dull and boring once she starts taking care of a small child full time. I don't think this was the intention of the author, though 
Here are a few of the books I have found head and shoulders above the rest. Some are quite challenging but also very rewarding imho. Search for my name under 50-Book Challenge threads for details on most of them:
Biographies/autobiographies:
Alan Turing: The Enigma
The Strangest Man (Paul Dirac's biography)
Miracles Of Life (J G Ballard's autobiography)
Confessions of a Sociopath
Music In The Castle Of Heaven (Bach's biography)
Other non-fiction:
Quantum Theory Cannot Hurt You
My Stroke Of Insight
The Worst Journey In The World
Historical Fiction:
Measuring The World (about Gauss)
The Luminaries (about New Zealand's gold rush)
This Thing Of Darkness (about Darwin's 5-year voyage about survey brig The Beagle)
Middlesex
Sci-Fi:
Classics - Dune, 2001: A Space Odyssey, 1984, The Foundation, Time Enough For Love.
Hyperion
Neal Stephenson's books: Snow Crash, The Diamond Age, Anathem, Cryptonomicon.
Jonathan Strange and Mr Norrell (about magic, so fantasy not sci-fi)
Fiction:
Cloud Atlas
Anna Karenina
The Goldfinch
Umbrella
The Atrocity Exhibition
The last two are not only difficult to read but also likely to mess you up for weeks, so approach with caution. Great books, though 