David Weber's "Honorverse" ships follow the known rules of physics, plus a little bit of hand-waving for the FTL without which it's almost impossible to write space-based science fiction. I would say that his portrayal of space combat is as "hard sci-fi" as possible in any setting which includes FTL. (The rest of his universe ... well ... two words: psychic cats. Meh.)
Weber's mathematically lavish world of acceleration-derived velocities and velocity-derived intercepts ruined me for other less rigorous offerings.
Star Trek is poorly-written incoherent crap -- why is detection so inconsistent? Sometimes they detect ships well outside "weapons range" (whatever that is -- Weber would both know the answer and tell you) and sometimes the episode begins with the Enterprise being fired at before anyone has even noticed another vessel is in the vicinity. Apparently in Roddenberry's Utopian future space ship crews won't post a watch -- no matter how badly they might need to.
Trek's "rules" are whatever the writers need them to be at any given time. Need suspense? You've spotted several Borg cubes at extreme range. Need action? "Captain! We're under attack by a Borg cube!" Darn, wish we'd seen it sooner. Need a contrived conflict? The Foreheadgluians' star is about to go supernova while the Foreheadpastians need a cure for a disease delivered within 24 hours. Never mind it's a trillion-to-one coincidence or that no one knew in advance of the star's impending demise. Need writers who don't insult your intelligence? Good luck with that.
Star Wars is even worse: how do you not know in advance there's an "asteroid field" until, hounded by an enemy pursuit, you suddenly notice there's an asteroid field ahead? You can see that stuff from billions of miles away, plus it would be charted. You wouldn't "accidentally" fly into the orbit between Jupiter and Mars then notice -- what serendipity! -- there were lots of asteroids. And if you did you wouldn't be treated to a densely-packed debris field into which you could fly your ship and hide. Think of the distance between the Earth and the moon. Even if we had 300 moons you still wouldn't need fast reflexes and fancy flying to duck, dodge, and weave to avoid them, and at sublight speeds it would still take you several minutes to get from one to the other. In space the distances between objects is enormous. The only place you could maybe run into problems is in low planetary orbit around a low-tech civilization that doesn't clean up its space junk (*cough* *cough*).
Virtually no object in space larger than a molecule is so common that you could encounter it by chance, and virtually no object in space larger than a snowball wouldn't already be studied, catalogued, and charted in the shipboard computer equivalent of Googlemaps. We have names for most of the larger asteroids and we haven't even visited one yet.
Sorry to rant, but there's forgivable "Fridge Logic" and then there's "WTF?" 3 seconds into the story. Almost all space-based sci-fi falls into the latter category. Stargate Universe is surprisingly good so far, FWIW.
David Weber uses what amounts to extra dimensions and gravity waves to get the fridge logic of his FTL to work. In the differing "gravity bands" space is compressed so that less distance traveled in a higher band translates to more distance traveled in a lower band, and reality sits at ground-state relative to all that. All the gravity wells in all the universe contribute their perturbations to the great ocean of gravitational currents in the gravity bands, and ships "sail" that ocean using those currents. Intense gravity wells make translation into higher gravity bands impossible, so it's back to Einstein and Newton around objects of interest like stars and planets, conveniently forcing all the important action follow the laws of physics with which we're familiar.
In Weber's world it's all about the fleet's maximum acceleration, relative velocity, and the powered missile engagement envelope (missiles could fly indefinitely in space but can only maneuver while they have power.) Weber does the math and shows his work, but also relates important events (entering engagement range, time to zero / zero intercept [zero velocity at zero distance], etc.) in terms of time so the casual reader can relate (I've never checked Weber's math, but I find it comforting that I could). Reading Weber you never ask yourself, "Why don't they just do X?" where "X" is some common-sense solution built upon the real laws of physics. Instead you're gripped by the suspense and the danger -- a danger you understand because Weber's given you specifics -- and you're asking yourself, "How are they possibly going to survive this time?"
