To the Lighthouse by Virginia Woolf is such a classic of modern English literature that I fear I can't add anything to the discussion other than to say how much I appreciated it. I loved the thoughtfulness of the writing, how Virginia would cover a scene from several points of view, and how characters would argue with themselves.
In the Book Thief by Markus Zusak, author uses a rich, multi-layered blend of allegory, metaphor and symbolism to create amidst the dirt and depression of Germany during the late 30s and 40s a stark vision of historical and philosophical thoughtfulness.
Reading Catch-22 was sort of like watching a brilliantly shining coin flipping through a majestic parabola in slow motion, with one side representing laugh-out-loud comedy and the other an intense exploration of the terrors of war, making its way to the ground with the weight of someone's fate resting on whichever side it falls on.
The George Orwell Archive also contains the first jottings of the most well-known words and phrases from his books; including 'War is Peace, Freedom is slavery, Ignorance is strength' from Nineteen Eighty-Four.