For all the sci-fi war freaks....
Forever War - Joe Haldeman.
I remember my dad lending this to me when he got it new in 1980, and I still have the same copy (with much added sellotape) which I must have read about 15 times since. Would recomend the editors edition which has material cut from the original release.
Also some good reads..
World War Z by Max Brooks
Sunstorm by Arthur C Clarke and Stephen Baxter
Six Elric books (Elric of Melnibone through to Stormbringer) by Michael Moorcock
I, Robot and The Complete Robot by Issac Asimov
I could go on....