X2: The Threat is an awesome game, and it's free on GameTap.
It's a space sim whose scope surpasses DEREK SMART DEREK SMART DEREK SMART's Battlecruiser games, allowing bounty hunting, trading, piracy, passenger transport, freight hauling, production, and even full-blown fleet management as potential ways to bring in money and advance yourself. It has a dynamic economy that functions based on supply and demand, and one can quickly make money by buying a factory's products and selling them to a factory that uses said product as a resource. The prices fluctuate based on how much of a resource or product the factory has.
If you have enough money you can even buy your own factories from the shipyard and set them up, but you'll require a very large ship(The Human version is called a Mammoth) to carry the station. Once you've made enough money(Or if you win the lottery, it's a very low chance, but one jackpot I saw was over 78 billion credits) you can buy a capital ship and your own fleet. The game has tiny monitors on the corners of your screen you can activate to see turrets, computer-controlled ships, and other assorted goodness, and you can purchase software for ships that makes them as good(Or better, if you suck) as you for doing tasks, and they can even be used to trade while you're off grappling with giant Kha'ak(Had to, sorry, you'll see in a minute)
I haven't gotten far enough into the game to determine the quality of the storyline, but character models and voice acting are both lacking, probably due to the fact that the spaceships own so hard. All I know is that there are geometric aliens known as the Kha'ak(Pronounced the way you think, I don't know what the writer was thinking when he did that, jokes abound) and you fight them, or something, I've only beaten the second mission(Which sucks by the way, without giving away the plot, imagine flying a 747 with a forcefield and impenetrable armor, being chased by quadraplegics in MiG jets. It was cool as first, as I flew across the surface of the human flagship, The Argon One, chased by pirates, and turned the whole ship sideways to fly between the fire of two heavy turrets on the surface of the ship; but eventually it became frustrating and tedious, because my turret couldn't kill the enemies, and I had to rely on fighter support.
Other than capital ship combat, which I haven't seen enough to pass judgment upon, combat is nothing to really write home about. Mouse or Joystick based flight, try to aim at the little moving circle. Turrets are a bit sluggish, and seem to really love inertia, so you'll overshoot the lead indicator a lot. It's best to just give it computer control and fly the ship, as the computer is a crack shot.
EDIT: Forgot to mention, there are some minor flaws in the game world that could damage suspension of disbelief if you're a hardcore roleplayer. When you request docking permission, the automated interaction system says "Positive" instead of "Affirmative". Quantum Tubes are also known as Planck Tubes, despite the fact that in the X Universe Earth is an almost mythical place, and no one has seen it in hundreds or maybe thousands of years. It's very unlikely they'd know about Max Planck. This isn't that serious though, the rest of the game is very good, and it's not nearly as obtuse as the Battlecruiser games.
I'm not good at conclusions. Post is over.
[ May 17, 2008: Message edited by: Cthulhu ]