Surely almost anything with much of a plot. Time Traveler's Wife, if I'd even bother with it again, Extremely Loud and Incredibly Close, Out by Natsuo Kirino, Life of Pi by Yann Martel. Books that you read and the plot is way beyond anything you could ever imagine: Sophie's World by Jostein Gaarder.
Lolita et al., books by Dostoyevsky, James Joyce, etc are books that I am grateful for having read once (or a number of times) before. The reading experience isn't 'spoilt' by knowing what happens. One exception is maybe Mary Shelley's Frankenstein.
Tolkien's stuff are the books I would erase the first time just to not bother with them again, though The Hobbit was okay, I guess.