1. Weir of Hermiston
2. Sanditon
3. The Love of the Last Tycoon/F. Scott Fitzgerald
4. The Castle/Franz Kafka
5. The Mystery of Edwin Drood/Charles Dickens
6. The Garden of Eden
7. No. 44 (alternate title: The Mysterious Stranger)
8. Answered Prayers
9. The Ivory Tower
10. Juneteenth/Ralph Ellison
11. The Original of Laura
Most of these were left unfinished by the author's death, but in at least a couple of cases, the author abandoned the work years earlier. In all cases but one, the work was published posthumously, but in one case, the fate of the novel is still uncertain--the estate may destroy it because of the author's wishes. Any books I'm overlooking?