I am a huge fan of Attack Vector: Tactical (AV:T) and have owned a hard copy of the original for a decade. I was delighted to see it made available in .pdf form recently and snapped up a copy as my board-game rules library is now stored on my tablet.
The game is the first (and in my opinion) best in the Ad Astra Games space combat stable which also includes the Saganami Island Tactical Simulator (spaceship combat in the universe of David Weber's of Honor Harrington) and Squadron Strike which takes the core of this game engine and applies it to cinematic space combat.
In Attack Vector: Tactical movement is fully 3D and fully Newtonian. Accelerations alter as reaction mass is shed and accelerations cause displacement (the most frequent omission in space combat games). Pivoting takes into account moments of inertia. Beam weapons, kinetics and missiles all have energy values for their launch, waste heat and damage. Damage is calculated from the direction the ship is hit, the weapon damage profile, the effect of ablative armour and the internal structure of the ship.
This amount of detail, and dare I say, realism, comes with a significant complexity overhead. However, the game design is very elegant and the game does most of the calculations for you. You really can concentrate on flying the ship and making the best use of your weapons load-out. Turns take about 20 minutes (a bit less with experience) and a full game lasts 8 - 18 turns. It's a high-complexity war-game, but tremendously rewarding to those willing to take the plunge.
The bundle comes with the latest version of the rules (162 pages), several very detailed walk-through tutorials to learn the game, 15 ship types with two more downloadable from the Ad Astra website when you register your game, a fully developed setting (called "The Ten Worlds") with defined politics, economics and histories, including 15 historical scenarios in the form of key battles along with 3 campaigns and a further 9 "Hypothetical Scenarios". You can easily use it as an RPG setting, even incorporating the game for ship to ship combat within the RPG.
The main omission for this type of game is the lack of ship design rules - the process is basically far too complex. However, the large number of ship types and scenarios mean this has practically no impact on replayability (if you really want ship design rules, check out Squadron Strike, which is simpler by a long chalk and the ship design still requires a vast spreadsheet in Excel with an array of options so bewildering it makes my head hurt. So much so, that I always use the pre-designed ships).
AV:T is heavily simulationist at its heart, re-creating the tactical decisions of real space combat on your table-top. If you're looking for swooping fighters and lumbering capital ships then you can safely move on to any number of 2D "space" combat games. If you really want to explore how Physics will determine the nature of ship to ship combat in space then this is the holy grail.