Okay, so I already posted this; but I can't stop thinking about Thomas Pynchon's Gravity's Rainbow. I've been revisiting it lately for my exam prep and it's just a phenomenal book. I know there are lots of people here who love Cormac McCarthy's Blood Meridian; well, I honestly think that Gravity's Rainbow is on par with that novel, and in fact is far more stylistically/narratively complex.
Of course, that's to be expected: Blood Meridian is a historical novel, and Gravity's Rainbow, while historical to a degree, is far more interested in the unknown and the alien. And this is why I think several readers on this board would find the novel fascinating, albeit challenging. Gravity's Rainbow is a work of, for simplicity's sake, horror in its purest sense: the invasion of the living human world by the world of the inhuman dead. War in Pynchon's novel isn't so much an act of aggression between two (or more) human factions, but an interface between life and death. War is a means of communion, so to speak. This allows Pynchon to make some really sweeping political critiques as far as militarization goes, but he also takes aim at race, gender, sexuality... and in the realm of science he tackles physics, mathematics, cybernetics... he's all over the board.
It's by no means a simple narrative, and I do not claim to have a complete grasp on what exactly happens in it. But every time I go back and look at it, I find something new to underline or notate. It's just an incredible piece of literature.