"War of the Ring" was to be the title of the third installment of the Lord of the Rings trilogy, after the publishers decided to split J.R.R. Tolkien's huge saga in three books. The author favored this title, but did not get his way and the book was called The Return of the King. Tolkien felt that this title spoiled the plot by giving away the return of Aragorn II to the kingdom of Gondor.
If used, Tolkien's title would have spared us of many infamous spoiler jokes before the release of Peter Jackson's Return of the King.