Arvoch Alliance is a pretty good mission based space sim, it's pretty low budget, and not really concerned with telling too much of a cinematic story, but the game has a good variety of things to do in it.
http://www.starwraith.com/arvochalliance/
there is another one i am trying to think of
Also Independence War, although it's less fighter pilot and more frigate action, thus slighty harder, awesome storyline too.
http://www.gog.com/game/independence_war_deluxe
Tachyon The Fringe is a great wing commander style game too, and the main character is voiced by Bruce Campbell, epic win
http://store.steampowered.com/app/32760/
Having a LOT of fun with Elite Dangerous too, Freelancer done right.
http://www.elitedangerous.com/
Just about everyone is excited, or atleast aware of star citizen by this point, give that look when it comes out
https://robertsspaceindustries.com/about-the-game