The Glitter Jungle - Primarily Giles/Ethan pairing. This site also features fan fiction from several series. - http://www.femgeeks.net/glitterjungle/fic.html
The Watcher Chronicles - Stories by GylzGirl rated PG-13 and under. - http://www.midnightlore.net/anthonyhead/watcher/index.html
Once More With Feeling - Anthony Stewart Head appreciation site featuring to fan fiction, fan art, photo galleries, and related links all dedicated to the character Giles and the actor who plays him. - http://www.wickedsky.com/oncemore/omwf/
Bodice Ripper - Archive of stories focusing on Giles/Ripper. Various genres and authors. - http://bripper.drakeleather.com/index.shtml
Adds Mystery - Contains a variety of pairings, mostly slash. Some Giles stories. - http://home.comcast.net/~wesleysgirl/fanfiction.html
Oakpark Street - Giles-centric Buffy the Vampire Slayer fan fiction. - http://www.inner-moppet.net/oakpark/
Realm of the Tweedy Book Guy - Rupert Giles fan fiction, wallpaper, banners, and links. - http://www.tweedybookguy.co.uk/