OK, first link - actually, not a single link, more of a webring.
"The Alliance" started back on the old CIS Compuserve FLIGHTSIM Forums, and made the move to the WWW somewhere between 5-8 years ago. It is made up of a loose collection of independent "squadrons" whose original intent was to play the old Star Wars: X Wing series space combat simulation games, fan fiction (normally partly-RPG based) and fan art. Since LucasArts stopped making the X Wing games, the groups have quietened down somewhat, but most retain their old fanfic archives online.
The stories can be violent, with a hint of romantic/sexual overtones but generally are not explicit (they tend to stick reasonably well to the Star Wars "ethos" on such matters).
So, the links:
Wolfshead Squadron (see the Reading Room)
CRS Morningstar (see the Lounge)
CRS Vigilant (see the Lounge)
The quality of the work is variable across the three sites I've linked to. However, I'd personally recommend any of the stories by Dario "Ibero" Pozo - you'll find them on the Wolfshead site.
Enjoy!
Nice Mike