I for one am totally looking forward to seeing what everyone has to share from and about a favorite book.
For me, Ulysses by James Joyce remains a big favorite. Though it's a book best read in a class or (at least) with others who can help you puzzle through the confusion--which was absolutely deliberate on Joyce's part--it inevitably becomes a fabulous book to return to. I recommend it heartily to students all the time.
The BBC has prepared a hilariously abbreviated version of the novel here, and the comments include lots of jibes from the haters, if that gives you any comfort.
Here, the first few paragraphs. (Note Joyce's stubborn refusal to abide by quotation punctuation.)
Stately, plump Buck Mulligan came from the stairhead, bearing a bowl of
lather on which a mirror and a razor lay crossed. A yellow dressinggown,
ungirdled, was sustained gently behind him on the mild morning air. He
held the bowl aloft and intoned:
--_Introibo ad altare Dei_.
Halted, he peered down the dark winding stairs and called out coarsely:
--Come up, Kinch! Come up, you fearful jesuit!
Solemnly he came forward and mounted the round gunrest. He faced about
and blessed gravely thrice the tower, the surrounding land and the
awaking mountains. Then, catching sight of Stephen Dedalus, he bent
towards him and made rapid crosses in the air, gurgling in his throat
and shaking his head. Stephen Dedalus, displeased and sleepy, leaned
his arms on the top of the staircase and looked coldly at the shaking
gurgling face that blessed him, equine in its length, and at the light
untonsured hair, grained and hued like pale oak.