A little more recent one that is very gritty, though it involves herion addiction, too (of the author), is My War Gone By, I Miss It So, by Anthony Loyd. He became a photojournalist and covered the Bosnian war and then later the war in Chechnya. A good one on Vietnam is Street Without Joy by Bernard Fall, a French journalist who was killed covering the American part of the war. It's considered one of the finest accounts of Vietnam.
Lastly, I HIGHLY recommend Frontsoldaten by Stephen G. Fritz (Kentucky Press). It's based on the diaries and letters of common German soldiers during WWII, and it is absolutely the most vivid account of war I have ever read (and I've read hundreds of books at this point). It's a very obscure book, but I checked that it is on Amazon for $12. Seriously, this book will change your entire outlook on the war and what it was like to be a part of it.