I’m afraid I can’t make a ranking, but here’s a list of some male and female singers whose voices I like:
Men: Freddie Mercury, Adam Lambert, Sam Cooke, Elvis Presley, Roy Hamilton, Jackie Wilson, Smokey Robinson, Jussi Bjorling, Roy Orbison, Andrea Boccelli, Roy Khan, Luciano Pavarotti, Ray Charles, Otis Redding, Michael Jackson, Steve Perry, Brad Delp, Frank Sinatra, Paul McCartney, Eric Clapton, Marvin Gaye, Stevie Wonder, Roy Hamilton, Luther Vandross, Tim Buckley, Michael Bolton, Jeff Buckley, Robert Plant, Geoff Tate, Elton John, Billy Joel, Art Garfunkel, Bobby Hatfield, Bill Medley, George Michael, David Bowie
Women: Mariah Carey, Dusty Springfield, Janis Joplin, Grace Slick, Karen Carpenter, Celine Dion, India.Arie, Erykah Badu, Whitney Houston, Regina Spektor, Mama Cass Elliot, Aretha Franklin, Ella Fitzgerald, Leontyne Price, Maria Callas, Joan Sutherland, Tarja Turunen, Diana Damrau, Barbara Bonney, Barbra Streisand, Alanis Morisette, Kate Bush, Tina Turner, Diana Ross, Kelly Clarkson, Minnie Riperton, Ann Wilson, Pat Benatar, Dolly Parton, Bonnie Tyler, Annie Lennox, Tori Amos, Lauryn Hill, Tracy Chapman, Cyndi Lauper, Norah Jones, Toni Braxton, Alicia Keys, Nina Simone, Etta James, Joan Baez, Joni Mitchell
I don’t necessarily listen to all of them, but I at least like their voices. I tend to prefer female singers in general, I think. I could certainly think of more, at any rate.