Artists with most cumulative weeks at #1 on radio since Oct. 1984 (including group numbers for solo artists)(not an exhaustive list):
Mariah - 93
Rihanna - 62
Beyonce - 58
Usher - 50
Boyz II Men - 50
Alicia - 35
Janet - 34
T.I - 33
Madonna - 30
Justin - 28
George Michael - 28
Whitney - 26
Celine - 26
Bruno - 25
Nelly - 23
Jay Z - 21
Ludacris - 21
Maroon 5 - 21
Gwen - 20
Phil Collins - 20
Kanye - 19
Paula - 19
Eminem - 19
will.i.am - 19
Goo Goo Dolls - 19
J. Lo - 18
Sean Paul - 17
Christina - 16
Katy - 15
Ace of Base - 15
TLC - 15
Adele - 14
Michael - 12 (doesn't include Off The Wall or Thriller eras)
Jewel - 12
Ashanti - 12
Jamie Foxx - 11
Pink - 10
Pharrell - 10 (not including production)
Ciara - 9
Taylor - 6
Ellie - 5
Prince - 3 (When Doves Cry and Let's Go Crazy were right before the chart started)
Gaga - 2
Kelly - 2
Nicki - 1
Britney - 0 ;__;
Mariah - 93
Rihanna - 62
Beyonce - 58
Usher - 50
Boyz II Men - 50
Alicia - 35
Janet - 34
T.I - 33
Madonna - 30
Justin - 28
George Michael - 28
Whitney - 26
Celine - 26
Bruno - 25
Nelly - 23
Jay Z - 21
Ludacris - 21
Maroon 5 - 21
Gwen - 20
Phil Collins - 20
Kanye - 19
Paula - 19
Eminem - 19
will.i.am - 19
Goo Goo Dolls - 19
J. Lo - 18
Sean Paul - 17
Christina - 16
Katy - 15
Ace of Base - 15
TLC - 15
Adele - 14
Michael - 12 (doesn't include Off The Wall or Thriller eras)
Jewel - 12
Ashanti - 12
Jamie Foxx - 11
Pink - 10
Pharrell - 10 (not including production)
Ciara - 9
Taylor - 6
Ellie - 5
Prince - 3 (When Doves Cry and Let's Go Crazy were right before the chart started)
Gaga - 2
Kelly - 2
Nicki - 1
Britney - 0 ;__;