A cross between Angel and Buffy the Vampire Slayer finds Giles and Angel kidnapped and put on trial by a clan of the Kalderash tribe in GYPPED.
What are the TOP TEN SIGNS YOUR SCHOOL IS ON A HELLMOUTH?
Ethan Rayne kidnaps Giles and Willow and sends them to another dimension, where flashbacks reveal what happened just after the Eyghon demon affair and why Giles always greets Ethan with a beating, plus we get dragon horses, a bridge over troubled water, and Elvis--sort of--in MUSIC, MAGICK, AND MAYHEM. Rated PG-13 for violence.
Parts 1 through 4.....Parts 5 through 7.....Parts 8 through 10.....Parts 11 through 12
In A Healthy Mind in a Healthy Body," COW sends a health insurance agent after Giles, and the Scoobies struggle with a Seezik Serpent at the Wilkins Memorial Pool.
Check out the "adult" section (if you're old enough) for a story about Giles being kidnapped by vampires and the Scooby Gang's reactions.
Anything by K. V. Wylie. Start with "Willful Endings," in which we learn of Giles's past (AU) history with Drusilla. Intense, moving, and very real. She also does a magnificent Giles/Cordelia series--yes, I winced, too, but her Cordelia is blunt and self-centered and yet lovable, and you'll believe they could be a couple when K.V. Wylie gets through with you. Buffy/Giles relationshippers who are old enough will enjoy "Danube's Choice" and its sequels (if you find them; they're not at this archive any longer). There's also a non-adult B/G series, SEW THE CHICKEN. Heck, just read Wylie--even the non-BUFFY stuff is great.
You must read Kris Wahlberg's massive, moving, detailed AU series, still (dammit!) unfinished. We get a descendant of Morgan LeFaye, a Giles family (alive and dead, past and present), the Wild Magic, Jack the Ripper, Whiny Wesley becoming less whiny, ghosts, love, death, violence...it's not to be missed.
J.K. Philips claims the BUFFY trilogy DEATH BRINGS CLARITY is her first attempt at fan fiction. With writing this good, she's going to set the fanfiction world on fire. (She does it fast, too, so you won't have to wait too long for the finish.) It opens with a gripping Angelus torture scene that reveals to Giles that he loves Buffy, and leads to a vampiric Watcher/Slayer pair who want to bring Buffy back to make her--and Giles--a similar pair, a truly unique way to return Buffy from the dead. Buffy/Giles relationshippers will love the way the trilogy progresses. Philips makes you believe in Giles as a father, teaching his three-year-old son not only our alphabet, but the Sumerian one, too. (I like Xander the babysitter getting tied to the bed by the toddler, too; luckily Giles has also taught his son never to invite anyone into the house....)There's plenty of angst ahead for Buffy and Giles, with appearances by the ANGEL characters and Uncle Spike. Marvelous.
Visit harriet_the_spy's BLOOD AND CHOCOLATES page for some great Giles stories. Try Serves the Whirlwind, set just after "Becoming 2," with Giles struggling to deal with his pain, his anxiety over the missing Buffy, Joyce's anger (As Ethan remarks, "I've seen many dreadful things in my time, but none more gruesome and terrifying than the American soccer mom."), and Ethan's latest scheme. It's a great examination of the Ethan/Giles relationship, with Ethan by turns snide and self-centered and loving, and it's written with insight, humor, and understanding.
Try Jeanne Devore's "Turnabout," in which Jennie Calendar, having shot Giles in the buttocks with a crossbow bolt during "Ted," must get him to the ER and home while dealing with her feelings.
Xenon has a series of tales about Ethan and Ripper, as well as "Violence of the Sun," in which squabbling Spike and Giles battle a vengeful demon. ("You were...well...licking your lips. It's a bit off-putting."
"It's meant to be." Spike dug his hands into the pockets of his much-stressed leather jacket. "It's midnight, and you're sitting in a graveyard with a vampire. Of course it's bloody off-putting.") They find they have more in common than they believe possible. Equally wonderful is "All Made of Wishes," in which Ethan is up to his usual ill-thought-out tricks; he creates a universe where the Mayor did ascend, Faith tortured Giles to death, and Sunnydale lies in ruins. Ethan reacts with typical terror, though mustering up the nerve to help Giles when it counts. Angelus puts in an appearance, too.
Come Christmas-time, if you're in the mood for sentimental and smarmy adoration of Giles--and who isn't?--try Gail Christison's "The Wishes." Yes, Virginia, there is a Mr. and Mrs. Claus... Then go to her fanfiction page and try "Times Two," an AU in which newly-mortal Anya summons the alternate Rupert Giles to get her necklace back, and Giles gets tortured while an anguished Angel watches.
Lest you think I only read massive opuses--opusi?--I also recommend cyberwulf at www.fanfiction.net; this Irish author specializes in vignettes with solid Spike and Giles characterizations. Try "In Twilight and Shadows" (Spike lies chained in the tub, listening to Giles's nightmares about Jenny and Angelus) or "Look But Don't Touch" (in a fit of malice, Spike decides to play mind-games on Giles, only to have the tables turned).
Like any intellectual Watcher, improve your knowledge by studying arcane texts such as Ms. Nitpicker's Guide to Writing Almost-Readable Fan Fiction.