A fantastic blend of atmosphere, story and riveting space combat. To this day whenever I hear "Luke and Leia's Theme" I can only think of viewing Azameen Home Base from space during the opening cinematic.
This is it: the last brilliantly made X-Wing game. It features a fantastic storymode, but you can just as well go shoot Tie-Fighters in the simulator. Don't forget to install some mods to make it shine just a little bit more on modern PC's.