TIGER'S MODERN by Tiger Hillarp Persson. 216 pp (Quality Chess 2005). 10/10.
This is one of the best opening books I have read for quite some time. Basically it's a repertoire for Black using the Modern Defence, 1 e4 g6, which involves an early ...a7-a6 as and where possible.
The author is candid and gives an enormous amount of original analysis in this book, which is rare indeed these days. We are treated to a feast of chess, with Hillarp Persson providing many of his own games to justify his recommendations. I will not spoil the surprise by giving too much away, but I will supply one of the games from the book: Ghannoum - Hillarp Persson. You can get a flavour right away.
If I were giving marks 10 out of 10 would be about right. Tiger's Modern ranks alongside Keene and Botterill's groundbreaking work of the 1970's and I can offer no higher praise than that.