Exercices de Style by Raymond Queneau.
This has to be one of my most treasured books. What makes this so special is again collaboration. This time between the author (Raymond Queneau), the designer (Robert Massin) and the illustrator (Jacques Carelman). This edition published by Gallimard in the late 70's has all the quality and attention to detail that Massin brought the great french publishing house.
The book takes the form of the same simple story firstly told in 99 ways using the original text by Queneau, supplemented and enhanced with typography and design by Massin. Then there are an additional 45 exercises by Carelman in which he explores the same simple story through illustrative styles.
You can pick up an english translation if you're interested in the literary exercises, but alas none of the typography or illustration is included in this addition:
There's also a wonderful book on Massin, published by Phaidon: http://www.amazon.co.uk/Massin-Laetitia-Wolff/dp/0714848115/
And for some more about Massin, Queneau, Oulipo and finding/collecting these books, check out this post over at Chancepress : http://chancepress.wordpress.com/2009/02/15/critical-massin-and-other-observations-about-book-collecting/