Next is Madonna!
Her #1s singles are:
"Like a Virgin" 1984, "Crazy for You" 1985, "Live to Tell";"Papa Don't Preach" and "Open Your Heart" 1986, "Who's That Girl" 1987, "Like a Prayer" 1989, "Vogue" and "Justify My Love" 1990, "This Used to Be My Playground" 1992, "Take a Bow" 1994 and "Music" 2000