If you were old enough to enjoy the wing commander series or if you are young enough to be curious about all the stories old timers like us tell, then the Freespace series is for you.
No joystick needed, play with the mouse and keyboard. Its on sale for $5.99 (digital distribution) as of March 22, 2010 at the link below.
in reference to: Freespace 2 - GOG.com (view on Google Sidewiki)
After you get it, google for mods.
Note: This is not a paid advertisment. I am just forwarding news to my readers. For more game sales, see the TPC digital distribution sale thread.