I did try to read The Count of Monte Christo and to be fair, the first third or so was good, dealing with the imprisonment and escape and so on, but then the whole thing stalled and got involved with these characters on a (very) long trip to Rome, and I realised that there was still another 1000 pages to go!
So I gave up....
There are so many bad books out there that it's hard to single one out, but for my money it has to be 'Miss Smilla's Feeling for Snow' for being such a pointless ending with our heroine stuck and floating endlessly on an ice floe. I felt the same, metaphorically!