Interesting thread. Glad I missed it.
But back to the OP.
There were only a couple of books that I've thrown away. The first one was
A Confederacy of Dunces.
I read it when it first came out and frankly have blocked it's contents from my memory. Normally, if I don't like them, I just give them away.
I went into the book expecting a very great read. By the time I finished it I was mad that I had wasted so much time.
If I were on death row and given the option of reading that book and prolonging my life, I'd throw the book away.
There will be some here that LOVED that book. It takes all kinds, I guess.