Marina & the Diamonds. Even though she didn't really flop she has only one #1 album in the UK and not even a number one single. She is unknown internationally. I really do think her next single 'How To Be A Heartbreaker' will break her into America and Britain. If it does it would've been a close shave for her as she only finished the song two weeks after the album released.
CHRISTINA AGUILERA
LADY GAGA
KATY PERRY
KE$HA
Marina & The Diamonds | Lana Del Rey | Gwen Stefani| Beyonce | Avril Lavigne| Britney Spears | Lindsay Lohan
Evanescence | Little Mix | Ellie Goulding | Guns N' Roses | Bon Jovi | Ariana Grande
Paramore l Iggy Azalea l Lil Kim l M.I.A l Bruno Mars
Justin Timberlake l Miguel l ASAP Rocky l Drake l Eminem l
Kanye West l Jay Z l Coldplay l Panic! At The Disco l Sean Paul l Macklemore l
Wiz Khalifa l T.I l Ludacris l Lady Antebellum l Conor Maynard l Calvin Harris
Nicole is not a flop, she did very very well in UK.
My favorite is Natalia Kills.
Jennifer Lopez / Nicole Scherzinger
Sirusho - Sara Jovanović - Jessie J - Cher Lloyd
Lena - Loreen - Bruno Mars - James Arthur - Amelia Lily - Jason Derulo - Little Mix
Tulisa - Olly Murs - Coldplay - Hurts - Havana Brown
Beyonce - Rihanna - Katy Perry