Twitney
Intellectually insulting nickname for Britney Spears or Whitney Houston, with which it rhymes.
"Jessica Alba will never be known as a Twitney. She's much too bright for that."
Twitney Spheres
This may resemble Britney Spears because it's based on her. It refers to any talentless hack who doesn't deserve success and adulation, even while doing whatever shameless thing it takes to command unwarranted attention and/or stay in the public eye.
"Oh, Kanye, stop pouting about not winning all those awards. You're acting like a Twitney Spheres."