Space Simulator wise, to this day, Wing Commander series is still probably the best way to go if you can get it to run on your computer naturally.

You could also look into Starlancer or Freelancer as well, those are not to bad. I also played Darkstar One for a bit, but it was ok

Speaking of Wing Commander and Freespace engine, there's a very popular fan made mod that's been in development for a very very long time. The prologue, for the big campaign that should hopefully come out sometime this year, came out.

http://www.wcsaga.com/

It basically takes place between the events of Wing Commander 3 and Wing Commander 4, and uses the Freespace 2 open source engine I believe. (Stand alone as well, and free)

Anyway, I'm plan on waiting for the full version whenever that's released, but if you check out the prologue of this, then let me know.