Flatspace 1 and it's sequel Flatspace 2. I prefer the sequel because it had more.... well, more stuff basically. And a story with an ending goal. Though this game was made as an neverending one...
It is a 3D space exploration with a top-down viewpoint. You can start out with pirating, bounty hunting, law upholding or trading. You choose what you wanna start out with but you can buy a bigger/smaller ship as you see fit when you have enough coins, get more crew to handle the inside of your ship and better guns and missiles.
Or do like I do, accept missions as a taxi driver, taking peeps from one sector to another, while trying to avoid attention by those darn pirates.
The soundtrack is the absolute best in this game!
A spotlight with the intro I enjoy. Edit. Never mind, I found the intro music here!
I've mentioned this game before, but it deserves to be mentioned more often. It is quite enjoyable and sometimes downright frustrating when you get hunted down by pirates.