M*A*S*H
The original source material for the film and subequently the very long running sitcom.
Set during the Korean war in a mobile army hospital this book follows Hawkeye Pierce, Duke Forrest and Trapper John as they try to stay sane working as field surgeons.
The book is funny, laugh out loud in places, but also satisfyingly dark at times. The only flaw is it’s brevity.
I’d recommend this one if you find dark humour particularly appealing, or are just curious about the starting point of a cultural phenomenon.