#1 weeks as lead artist, combining singles and albums:
Mariah Carey - a lot
Whitney - 57 weeks (or more counting a soundtrack)
Madonna - 51 weeks
Janet - 48 weeks
Taylor - 46 weeks
Beyonce - 44 weeks
Barbra - up to 39 weeks, counting soundtracks
Adele - 38 weeks
Rihanna - 35 weeks
Katy Perry - 35 weeks