Albums:
8,279,000, Christina Aguilera, 1999
4,383,000, Stripped, 2002
1,712,000, Back to Basics, 2006
1,015,000, My Kind of Christmas, 2000
707,000, Burlesque (soundtrack), 2010
530,000, Keeps Gettin' Better: A Decade of Hits, 2008
487,000, Mi Reflejo, 2000
325,000, Bionic, 2010
290,000, Lotus, 2012
128,000, Just Be Free, 2001
Top-selling digital songs:
6,507,000, "Moves Like Jagger" (Maroon 5 feat. Aguilera)
3,859,000, "Say Something" (A Great Big World and Aguilera)
2,406,000, "Feel This Moment" (Pitbull feat. Aguilera)
1,783,000, "Ain't No Other Man"
1,512,000, "Beautiful"
1,187,000, "Hurt"
1,184,000, "Fighter"
1,156,000, "Keeps Getting Better"
1,153,000, "Candyman"
746,000, "Just a Fool" (Aguilera With Blake Shelton)
With Aguilera's career predating the digital era, three of her songs have also sold more than 500,000 physical (CD/cassette) singles each: "Genie in a Bottle" (1,436,000), "What a Girl Wants" (605,000) and "Come On Over Baby (All I Want Is You)" (579,000)
More + info about Taylor, and Mariah at the link -
http://www.billboard.com/articles/co...rey?page=0%2C3