They seem like a nifty pairing, share dark pasts and had that summer together in England. (Unless there's a tribe of W/G shippers I don't know about somewhere.)

There was a lot of really fantastic W/G written in about 2003-2005. You can find a lot of it archived at
Bright Minds & Dark Magics (http://willowgiles.com/archive/).
Authors like Doyle, Gulessable, wisdomeagle, and Trekker (whose Corpus et Sanguis Season 5 W/G is what sold me on the pairing, and is sort of the gold standard for W/G for me) were active back then. Most of those authors have moved on from the Buffy fandom, or from writing fanfic altogether.

These days, gilescandy and naughtynyx88 are the W/G writers who are keeping the flame alive right now. I've written one bit of W/G fluff, and am currently working on an angsty AU Season 6 W/G. Unfortunately, my job currently involves working 60+ hours a week on an extraordinarily stressful project, and I'm helping my husband recover from a back injury, so I'm not getting much writing done lately. Hopefully soon I'll have more time to contribute more significantly to the small tribe. I do have a lot of ideas (many of them good, at least they seem that way in my head).