Well, as far as influential works go, commodorified's "With No Less Terror than the Elements" (http://community.livejournal.com/shaksper_random/7157.html) is probably the earliest piece in histories-fandom-as-we-know-it. And lareinenoire's "An Exchange of Favours" (http://yuletidetreasure.org/archive/83/anexchange.html) really kicked off the AU trend, which is still going quite strong... :)