Space Combat Sims I've known....
X-Wing: Not very realistic, but it works like an airplane sim for the most part (except there's no bank or yaw controls; you just turn), but hey, you get to shoot TIE fighters!! What more do you want? There's a Win95 version out there. You get access to X-wings, Y-wings, A-wings, and B-wings.
TIE Fighter: Somewhat like X-Wing, but it's got a better HUD and a wider array of ships and loadouts. You get to shoot X-Wings! You can fly TIE fighters, Interceptors, bombers, the Starwing Gunboat, the TIE advanced and defender, and the Missile Boat.
X-COM Interceptor: Controls are somewhat like X-Wing, but it does include vector control thrusters (so you can slide around) in the later game; you can also design your own spacecraft (within limits). I found the game somewhat short; it's not all space combat. Once you've done all the research you can pretty much win the war. There isn't much replay value, however.
Some I Don't Have:
The Descent series presents null-G flight, but it's generally indoors. Only Descent 3 has outdoor combat, and I don't think you leave the planet's surface.
X-Wing Alliance dates from 99-00 and is a 3D game. You eventually get to fly the Falcon into the Death Star II and blow up the reactor! Beats the trench run all cold.
Hope this helps!
TWK