I wasn't much of a Dawn fan when I watched the show and I don't think I'm alone in that, either. However, that changed when I started reading fanfiction. Dawn's one of those characters that has highly benefited from some serious character exploration by fic writers because we can take her out of the context of simply being Buffy's sister or the catalyst of conflict for Season 5, and really delve into who she is as a person. Each of these fics take one aspect of her and run with it to full affect.
1. The Down Below by Devil Piglet
Spike & Dawn, R, S7 post "Lessons"
Summary: Spike and Dawn have some unfinished business.
Review: Devil Piglet was one of the finest early Buffyverse writers we had and I miss her work dearly. While perhaps best known for her Spuffy, DP also created a number of fics that featured Dawn and I think this is one of her best. The show only gave us a glimpse of the animosity that Dawn felt for Spike after the events of "Seeing Red," but this fics takes those feelings of betrayal, hurt and vengeance to the next logical level. When did Dawn become so scary? I'd say just about the time this fic was first posted. A lovely, dark read with a beautiful conclusion.
( There's more to her than meets the eye )