http://www.mediaminer.org/fanfic/view_st.php?id=20515
While rather long and somewhat rough at the beginning, this is a fine story that focuses on Rei and her love for Usagi, along with a plethoria of villians, a few original characters, and tons of action.
It does have a lemony chapter (40, I think) and plenty of shoujo ai, so be warned.
EDIT: Kirika is currently refining the early chapters now that she's finished the story, so be aware of this.