Alright, I've found a good one to nominate. It may be too late to get it to fully nominated, but at least I can contribute in case anyone would be interested in reading it on their own:
Four Reigns by Kukrit Pramoj, Thailand
Though not so well known in the West, this book is very famous in Thailand and is considered as a major classic there.
From Goodreads:
This English version of the Thai novel Si Phaendin tells the rich and entertaining story of one woman's life both inside and outside the royal palace in Bangkok. Spanning a period of four reigns, from King Chulalongkorn to the reign of his grandson King Ananda, this popular modern classic gives insight into the social and political issues facing Thailand from the 1890s through the turbulent years of World War II. "Kukrit, famous as a journalist, wit, connoisseur of the arts, and, for much of his life, a politician, and once the prime minister. . . is also a world-class writer, equipped with imagination, humor, narrative skill, and keen understanding of human nature."--The New York Review of Books
Here is some more info on it (careful, I didn't read it all, though it may just be historical info it seems like there may be some book spoilers):
Four Reigns - a literary masterpiece
And here's a blog post about it:
Bangkok - Kukrit Pramote & Four Reigns