I can't remember whether or not I replied in here, and I can't be arsed to read all four pages. So in case I didn't say it before, I voted for Hilary Duff (by far).
I like all six of those listed, but Britney is the worst of the six right noe.
However, Soulja Boy, T-Pain, and all the crud rappers are easily worse than any of the six listed.
I really don't like this poll idea but if I HAD to choose, it's Britney.
Hilary I've liked since the beginning and supported her from the start, not the same for Rihanna since I was questionable on her when Pon De Replay came out and it wasn't until S.O.S. when I became a fan of her. Avril I've been up and down on (the down was in the Girlfriend/When You're Gone era, then bounced WAY back up when Hot was released) and the same for Kelly AND Christina. Kelly's down-point for me was when I got sick of Never Again and Christina's only down-point for me is that I was disappointed with Back 2 Basics. That leaves Britney who I have really been up and down, up and down.