FreeSpace 2 will forever have a special place in my heart. The best space fighter sim experience there ever was.
I hear that perhaps Elite: Dangerous is comparable, but from the videos of it I've seen, it doesn't have that military sci-fi feel to it. I miss the FreeSpace ambience, where you'd fly around in your fighter listening to the chatter between capital ships as they duke it out. I'm sad there was never a third part of the series; the storyline with the Shivans was excellent.
The AC series uses licensed real-world fighter jets but is set in a "near future" Earth-like setting. So there are sci-fi elements like giant flying aircraft carriers and enormous doomsday weapons such as giant railguns. The plots are enjoyably goofy, full of drama and plot twists. Lots of radio banter.
The overall "realism vs. fun" balance very closely approximates the good old spaceflight sims of yore like Freespace 2 and Tie Fighter.
AC7 is available on Windows as well as console, a first for the series. I put about 100 hours into it, and needless to say I really loved it. AC6 (Xbox 360) was great fun too; it may run on XBox One as well.
All AC games are all set in a shared fictional world ("Strangereal") but each game is a story about a different war and has a unique set of characters. So no worries about jumping into the series at some arbitrary random point; you're not going to be missing out on any context.
I'm not sure exactly what parts of the planes require licensing. Do you need to pay to use their names? Their likenesses? Both? Neither? Maybe it's just a courtesy? It's a good question. I'd love to know more myself.
A totally serious, military-accurate mood wouldn't quite work IMHO. Because then you bump up against realities like the fact that your jets are equipped with an absurd amount of missiles, and you will end each mission having shot down dozens of enemies, literally an order of magnitude more than any living pilot has shot down in an entire career.
So, I think the AC games walk the realism/absurdity line in just the right way.
I also highly recommend Wing Commander Prophecy Gold [1]
[0]:https://www.hard-light.net/forums/index.php?topic=94068.0 [1]:https://www.gog.com/game/wing_commander_5_prophecy
Another of the game's distinctive features is that instead of piloting a nimble but vulnerable space fighter, the player assumes the responsibilities of the bridge crew of a 160-meter corvette with a dry mass of almost 20 thousand tons! Even though for playability's sake the ship is capable of several-gee accelerations, there's definitely a tangible feel of inertia in how it responds to the helm controls.
The 16-minute, full-CGI intro video is probably one of the best introductions to any game ever, and definitely worth watching even as a standalone work of fiction: https://youtu.be/ECfKL4oS-6w