In the 'Unshelved' comic today

They have a banner that says 'Books that may irritate you.' Now I'm a librarian, and I, of course, love books. But everyone has a not-so-enjoyable book in their past. One that maybe didn't offend them, but irritated them somehow. Or kindled great repulsion, even. And so I'm asking a question:

What is your least favourite book of fiction that you've read from cover to cover and would rather go into a pit of vipers rather than ever open it up again?

Mine? Ernest Hemingway's The Old Man and the Sea. 'He looked at the fish, he looked at the sea.' That's all I remember about reading it in high school except that I found it terribly un-fun to read. I do love a lot of the classics (gravitating to things like the exciting Three Musketeers, the riveting To Kill a Mockingbird, or even the interesting Great Expectations, for example.) But Hemingway's was sheer torture for me, and I have never given any of his other books even half a chance, perhaps unfairly. I mean, really, the Book of Numbers from the Bible was more riveting, and it's primarily a dry census.

So, what's yours?