I adore fan fiction...I write it, I read it...I'm especially interested in unconventional couples (though I do have some conventional)...Some of my current favorites include:
BtVS/AtS - Angel/Cordelia, Xander/Fred, Willow/Jonothan
The West Wing - Toby/Donna, Oliver/Ainsley
Harry Potter - Hermione/Ron, Hermione/George, Hermione/Percy, Hermione/Oliver, Ginny/Neville
That 70's Show - Jackie/Hyde
Smallville - Lex/Chloe
Crossing Jordan - Jordan/Woody, Bug/Lily
The list goes on and on...I have written fic for someo of these pairings and many others that I will attempt to upload soon...