Gaga is great as well as Rihanna, but none of them will ever reach Elvis
and i believe the 1st album was Gaga's peak album
now if u say Adele, there is a chance, because she is quality and her voice, noone like her, no cheap/boring club songs like most modern singers do (copy each other)
don't mind my username, that was more than 10 years ago, I'm a different person now, amazing how people change ^_^