Rebecca

Daphne DuMaurier's Rebecca has one of the most famous opening sentences of any novel in the 20th century, followed up by a fantastic first chapter, very atmospheric and evocative.  From there, the story loses its drive for a while, but I was willing to cut it a lot slack from that first chapter.

I felt like it never quite regains the heights of the first chapter, but it regains its momentum once the planning for the fancy-dress ball starts, at about halfway through.  The reader knows something will go drastically wrong, and DuMaurier skilfully stretches out the suspense.  The last chapter of the novel is very rapid, which is just as well, because by that point it would be pretty easy to stay one jump ahead of the narration.  But I liked the understated way the novel ends, with no final confrontation between the narrator and Mrs. Danvers.  It fit in well with the sort of melancholic feel of the beginning.