There's a big difference here I think.

 

Kylie is quite well rounded in that her singles and albums sell quite steadily, however Anastacia always (GH aside) sells shedloads of albums but very few singles. If we're talking comeback singles then Anastacia definitely has the edge in my opinion, Left Outside Alone was huge and an excellent track. In the same breath i'm sure 2 Hearts will be huge but in my opinion it isn't a great track. As for the albums, you can't really compare them because no one has heard Kylie's yet. :lol: Still as someone else said it will easily shift 600k.

 

All in all I would say they're about even, the edge Anastacia has on her in albums Kylie makes up for in singles.

Definitely Anastacia, although overall Kylie is far superior