Black Eyed Peas. I couldn't take their huge generic transformation.
Beyonce. Still like her, but not as much as I did during Dangerously In Love & B'Day.
Ashanti. Back when she was relevant... but now her career is a mess (or over) so there's nothing for me to care about anymore.
Rihanna. I also didn't like her transformations.
Others: Janelle Monae, Nicki Minaj, Chris Brown, Justin Bieber (My World Era

)
I'm a little disappointed with Usher selling out, but he's still staying true to himself by releasing There Goes My Baby, Daddy's Home, Hot Toddy etc.