Stephen Crane’s classic American novel about a novice soldier during the U.S. Civil War has probably been adapted to audio more than once, but the version I heard was a feature length production from 2010 by The Colonial Radio Theatre. It’s a faithful, deliberately respectful version (according to the intro intentionally trying to maintain much of the language of the book — and utilizing the first person narration).
Admittedly, despite being a classic — or more likely, the reason it is a classic — is because it is a pretty straightforward story, about a young man experiencing the crucible of war, wandering through battles and the aftermath of battles, and less a “plot” with story twists and turns. And philosophically, it’s a brutal, unsentimental look at war without, quite, going so far as to be an anti-war story. Still, probably as good an audio production of the tale as you could want, with performances restrained enough to be effective, but with a slightly theatrical flavour, giving the thing an (appealing) Old School vibe, like watching some 1950s teleplay.