The Old Man’s War Series by John Scalzi is a fantastic space opera
As you know, I am a huge fan of B.V. Larson’s Star Force and Undying Mercenaries series. While I really enjoy Ryk Brown’s The Frontiers Saga and to a slightly lesser extent Jay Allan’s Crimson Worlds series, they take themselves too seriously and don’t rival the joy created by Larson’s fun light hearted tone.
I realize I am late comer to Old Man’s War, but I loved the series at every level. Scalzi blows your mind with varying imaginative concepts time and time again. The book pushes us to consider whether we would we be willing to sign up to fight for a potentially fascist organization about which we know next to nothing if it meant avoiding certain death from old age and gaining a young new body. It deals intelligently about relations between various sentient species and earth and its colonies. Best of all, it treats all these topics with a great sense of humor which makes the books extraordinarily enjoyable
Of the authors mentioned above, Scalzi is by far the better writer. His protagonists have rich inner lives. I also loved how he changes protagonists and even alternates between first person and third person narrative forms across the various novels.
Read the series, it’s fantastic!