House of Stairs. Crappy sci-fi by an author who was entirely too impressed by his own cleverness.
The Illuminatus Trilogy. I know a lot of people love it, but I got halfway through it before deciding that the whole point of the book was the author fucking with his readers.
Stars In My Pocket Like Grains Of Sand. Another sci-fi 'classic' that a lot of people love. I think it won some awards too, but I couldn't stand it. Interesting premise, but something about the writing style drove me up a wall.