Male:
15. R. Kelly
14. Robert Plant
13. Maxwell
12. Elvis Presley
11. Adam Lambert
10. Donny Hathaway
9. Al Green
8. Kurt Cobain
7. Frank Sinatra
6. Prince
5. Luther Vandross
4. Marvin Gaye
3. Michael Jackson
2. Stevie Wonder
1. Freddie Mecury
Female:
15. Tina Turner/Nina Simone
14. Barbra Streisand
13. Sade Adu
12. Amy Winehouse
11. Celine Dion
10. Janis Joplin
9. Florence Welch
8. Stevie Nicks
7. Kelly Clarkson
6. Bjork
5. Christina Aguilera
4. Aretha Franklin
3. Beyoncé
2. Mariah Carey
1.Whitney Houston
I personally think a great voice is part technique and part of what appeals to you. Even with that said some voices are undeniable.
I think Bey is a good technical singer but her voice doesnt resonate with many people. I think it has to do with the fact that her most popular songs doesnt showcase her voice.