Beyonce, Britney, Rihanna, JT, CB, Taylor, Fergie imporved with her solo career from BEP, Gwen always improves and Pink improves all the time cuz she's awesome!!!!
No one. Beyonce, Alicia Keys, Spice Girls, and Rihanna went up then down with consecutive albums; Justin Timberlake has like one good single (though that's more than zero) and N’Sync is 10x better, Taylor has only 2 things to compare so that’s not really comparable, Gwen improved from group to solo but then her second album sucked, Fergie only has one solo album to compare with group work, Pink's Funhouse and Britney's Circus are my least favorite albums from them, Kelly went up then slightly down, Christina…keeps getting worse. PCD and The Veronicas’ and Cascada’s first albums were 10x better than their second. Ashlee Simpson’s first album is by far the best; there is a reason it is her most successful. Avril’s 3rd album is her worst. Relient K’s last album wasn’t good, nor were the Backstreet Boys’s. Or J. Lo’s. Fefe Dobson, JoJo, and Paris Hilton’s stuff for second discs are worse than stuff for first ones. Confessions way > Here I Stand for Usher.