First, major respect and appreciation to the men AND women in uniform for their country in real life, and for the veterans and the families.
OK, if I was going to pick my favorite military man in uniform in SF, it would have to be Corporal Hicks in the movie "Aliens", as portrayed by Michael Biehn. I always go for that Southern accent and the man is not only good looking, he's calm, deadly with pulse rifle and can survive an Alien encounter.
A close tie for second would be Raleigh Becket and Stacker Pentecost in "Pacific Rim." Played by Charlie Hunnam and Idris Elba respectively, they cancel the Apocalypse and keep us all safe from alien Kaiju. (And the character of Mako Mori, played by Rinko Kikuchi, was wonderful!)
Then there's "Firefly" and Captain Mal...."Independence Day" with Will Smith's fighter pilot (although I actually preferred Jeff Goldblum's civilian character)...
When I'm writing science fiction, I almost always make the hero a Special Forces soldier in the Sectors military. (The Sectors being the galactic civilization where my SFR novels take place.) I think they're the most bad ass guys around, the kind of people I want to come rescue me, fight my way out of danger with and celebrate the victory in all possible ways together with. The quiet professonals, as we say of the modern day Navy SEALs.
In "Escape From Zulaire," Tom Deverane has served his time and would retire if he
In "Mission to Mahjundar," (cover reveal SOON, book out in August) Mike Varone has one last job to do before he takes early retirement to help his family out at home. The mission seems simple enough - find a downed ship and retrieve the casualties - until he's thrown into the local political intrigues, takes a detour to go tomb raiding and rescues a reluctant princess from her arranged marriage. But Princess Shalira, although blind, can channel the powers of the local gods and proves to be every bit his equal in solving the challenges they encounter.
The only easy day was yesterday, as the SEALs will tell you, whether you're on Earth or Out There.