Well... she certainly seems to be coming to that point in 'The Return'.
As for others, most of the ones to come to mind are dark stories, as it normally takes something fairly traumatic to change her personality that radically. Hmmm...
R-MULTI 'Realms' by Tamojin-Jeffrey Vasquez - [Status=Not Complete] - [Last Dld=06/29/2009] - [Size=1224kb] - [Files=11]
R-SM 'In Darkness In Fire' by Xzero - [Status=Complete] - [Last Dld=09/14/2005] - [Size=260kb] - [Files=15]
R-SM 'Twin Dragons Under Moonlight' by Ben Bradley - [Status=Inactive] - [Last Dld=07/08/2004] - [Size=731kb] - [Files=6]
R-SM 'Warriors of Light and Shadow' by Storm Bringer - [Status=Inactive] - [Last Dld=05/26/2007] - [Size=308kb] - [Files=11]
R-SM 'When Angel's Fall' by Innortal - [Status=Complete] - [Last Dld=01/06/2006] - [Size=109kb] - [Files=7]
I'd call the following a runner up:
R-SM 'Storms in Time Ranma's Story' by LeBibish - [Status=Not Complete] - [Last Dld=12/29/2008] - [Size=116kb] - [Files=4]
Also, were it ever continued, I would think she would have seen the mistakes made (certainly Pluto, Mercury, Neptune have) in the following:
R-MULTI 'Prices Paid' by Ar-Kaos - [Status=Inactive] - [Last Dld=01/04/2006] - [Size=227kb] - [Files=16]
EDIT, not a Usagi based story (Ami instead), but one that should fit well, would be:
SM 'Life's Blood' by Dro'gan NiteFlier - [Status=Complete] - [Last Dld=08/28/2004] - [Size=270kb] - [Files=9]
Heh... this marks the very first post to use the new status tags generated by my program.