Excellent suggestions above! The book that got me into the martial-arts was "The Manual of the Martial Arts" (1981) - Ron Van Clief ( I was 11 at the time).

Plus;

One Encounter, One Chance (Karate - Webster-Doyle)

It's a Lot Like Dancing (Aikido - Dobson)

Zen and the Martial Arts (of course)

Lung Ying Mor-Kiew (Chow Fook & CS Tang) - only if you practice the art...

Iron and Silk (Wushu - Salzman)

Anything by Dave Lowry (Autumn Lighting / Moving Toward Stillness)

The Classical Man (Karate - Richard Kim - much like Adam Hsu - very inspiring)

Steal My Art (T.T. Liang - Tai Chi)

Chinese Boxing (Robert Smith)

There are no Secrets (Tai Chi - Lowenthal)

Chronicals of Tao (Deng Ming Dao - largely allegorial piece)

The Way of the Warrior (Reid & Croucher) - good overview

Fiction:

All martial-artists should have read all 140+ books by Warren Murphy & Richard Sapir - Destroyer series - Sinanju (Remo Williams). They were written in the early 1960's and pre-date James Bond et. al who borrowed heavily from their work.

All martial-artists should have read Clavell's work (especially Shogun)

All martial-artists have probably read Eric Van Lustbader's series (the Ninja, Miko, etc.). It was great when it came out!!!

So many great books have been written on the arts - haven't seen a good new book in quite some time though...(not that I've been looking very hard though!)