Who had the bigger peak overall?
Mariah has:
Music Box - 32M seller contains the international smash hits Hero and WIthout You
Daydream - 25M seller contains the legendary hits Fantasy and Always Be My Baby
Mariah Carey - 15M seller with 4 #1's
AIWFC - biggest female hit ever?
Creating and making the pop/r&b/hip-hop fusion popular
Gaga has:
The Fame/ The Fame Monster
The Monster Ball Tour
My vote would have to go to the legendary Mariah Carey.