Inspired by JaoaP41's random thread, here are the top 50 most listened to female solo artists on Last.fm.
Artist - Total Listeners - Total Plays - Top 3 Songs in Past 6 Months
1. Madonna 1745009 57367601 Hung Up; Like a Prayer; Like a Vrigin
2. Rihanna 1734531 40123876 Disturbia; Russian Roulette; Don't Stop the Music
3. Lady GaGa 1573730 70370113 Poker Face; Bad Romance; Paparazzi
4. Britney Spears 1573511 69618593 Womanizer; 3; Circus
5. Beyoncé 1535780 35310138 Halo; Sweet Dreams; Single Ladies (Put a Ring on It)
6. Nelly Furtado 1442181 28513211 Say It Right; Maneater; All Good Things (Come to an End)
7. Avril Lavigne 1367224 47760608 Complicated; My Happy Ending; Girlfriend
8. Björk 1325593 51650599 Army of Me; Hunter; All Is Full of Love
9. Christina Aguilera 1319328 29344564 Hurt; Beautiful; Ain't No Other Man
10. Amy Winehouse 1301572 42188085 Rehab; Back to Black; You Know I'm No Good
11. Gwen Stefani 1202749 16650841 Hollaback Girl; Cool; The Sweet Escape (feat. Akon)
12. Kelly Clarkson 1197404 28706837 My Life Would Suck Without You; Because of You; Since U Been Gone
13. Lily Allen 1180370 35811885 Not Fair; The Fear; **** You
14. Dido 1178270 19934806 Here with Me; Thank You; White Flag
15. Norah Jones 1167913 32561872 Don't Know Why; Come Away with Me; Sunrise
16. Mariah Carey 1152772 24618631 All I Want for Christmas Is You; Obsessed; We Belong Together
17. Alanis Morissette 1126850 25596248 Ironic; You Oughta Know; Hand In My Pocket
18. Katy Perry 1124709 21613004 I Kissed a Girl; Hot N Cold; Waking Up In Vegas
19. Alicia Keys 1089705 22299844 No One; Try Sleeping with a Broken Heart; Doesn't Mean Anything
20. Kylie Minogue 1088308 22840298 Can't Get You Out Of My Head; Love At First Sight; In My Arms
21. Shakira 1047455 22861689 She Wolf; Did It Again; Whenever, Wherever
22. Regina Spektor 984065 46496105 Fidelity; Samson; Us
23. Fergie 935383 11526273 Big Girls Don't Cry; London Bridge; Glamorous (feat. will.i.am)
24. Nina Simone 899151 15667663 My Baby Just Cares for Me; Feeling Good; I Put a Spell on You
25. Sarah McLachlan 872370 13969398 Angel; Silent Night; Building a Mystery
26. Tori Amos 870260 35518241 Cornflake Girl; Winter; Crucify
27. Aretha Franklin 854370 9436928 Respect; I Say a Little Prayer; Think
28. Leona Lewis 846887 13571181 Bleeding Love; Better in Time; Happy
29. Jennifer Lopez 820977 9303584 Get Right; If You Had My Love; Love Don't Cost a Thing
30. M.I.A. 809027 21119149 Paper Planes; Boyz; Jimmy
31. Natasha Bedingfield 806545 9496098 Unwritten; Soulmate; These Words
32. Fiona Apple 806095 17174016 Criminal; Paper Bag; Extraordinary Machine
33. Ella Fitzgerald 785432 10403525 Sleigh Ride; Someone to Watch Over Me; Let It Snow! Let It Snow! Let It Snow!
34. Enya 769062 25298822 Only Time; Orinoco Flow; May It Be
35. Sheryl Crow 760817 8520037 If It Makes You Happy; All I Wanna Do; Strong Enough
36. Janis Joplin 745286 10727961 Me and Bobby McGee; Piece of My Heart; Summertime
37. Duffy 730805 11216311 Mercy; Warwick Avenue; Stepping Stone
38. Cyndi Lauper 725433 6504979 Time After Time; Girls Just Wanna Have Fun; True Colors
39. Kate Nash 723578 18155167 Foundations; Mouthwash; Pumpkin Soup
40. Billie Holiday 715874 11985657 God Bless the Child; Strange Fruit; Easy Living
41. Natalie Imbruglia 708597 7476863 Torn; Shiver; Wrong Impression
42. Whitney Houston 705708 7049078 I Will Always Love You; Million Dollar Bill; I Wanna Dance with Somebody
43. Janet Jackson 700377 9450546 Feedback; That's the Way Love Goes; Together Again
44. Ciara 699027 8003381 Like a Boy; Promise; Hotline
45. Céline Dion 666729 10561325 My Heart Will Go On; Because You Loved Me; It's All Coming Back to Me Now
46. Corinne Bailey Rae 641177 8201434 Put Your Records On; Like a Star; Trouble Sleeping
47. Sade 638152 10362041 Soldier of Love; Smooth Operator; The Moon and the Sky
48. Mary J. Blige 635313 7856620 Be Without You; Family Affair; Real Love
49. Colbie Caillat 631053 10256333 Bubbly; Fallin' for You; Realize
50. Ke$ha 625923 12368693 TiK ToK; Your Love Is My Drug; Take It Off
I had to do this by hand, so I feel like I missed a majorly important artist. If you think of one, please tell me!
I didn't expect that 
