Three military scifi classics: Forever war by Joe Haldeman, Ender‘s Game by Orson Scott Card and Old Man’s War by John Scalzi.
Discussion
Richard Morgan - Altered Carbon + Market Forces
I hate to say it but I'd swap out forever war and insert Stainless Steel Rat or maybe Starship troopers
Have to agree on forever war, it carries weight because the author was a Vietnam vet, but Oldman's War was a fantastic