Britney, Beyoncé, GaGa, Eminem for sure. Maybe Katy too.
I don't know why so many people mention Adele. She's talented & has a great music but i still don't see her lasting that long. You need much more than good voice to stay relevant for so long. I see Adele being another Leona Lewis success & longevity wise.
She's a musician, not just a recording artist. She will keep writing songs and release them even if she's not the "it" girl anymore. Any label would sign her.
Adele, Katy Perry, Gaga, Ameriie (of course), Lil Wayne, Eminem, Christina Aguilera, Kelly Clarkson, Bruno Mars, Drake, Britney Spears, and Rihanna. That's its!
Why you guys can say that Ke$ha can't is beyond me... I am not going to be delusional and say she will, but I think we can all agree that we have to see what happens with album #2 ...
The underdog of reinvention...from R&B to Gospel, Pop and Dance. Oh and you can't forget the numerous leading lady roles on the most prestigious stages...
Heart to Yours 2002
Do You Know 2004
Unexpected 2008
Tenitra Michelle Williams definately has a few more albums to go. She is yet to release a straight, contemporary R&B album and has stated that she'd love to make a jazz album
Im not sure if we are still alive til they make it to the 10th.... just wondering...
anyway someone is right, ADELE really needs to take care of her health and voice.. people with a lot of emotions like her and AMy are easy to get upset and ruin their life.. believe me im not trying to make bad things happen but ADELE needs a good life.. if she gets upset its dangerous.. she looks very vulnerable...
, she won't.
7 of them are international 
the 8th is cooking 