Mariah and Whitney transition between soft whispers and super loud belts better than any of these other chicks. I'm willing to say the only real differences between Mariah and Whitney are their tones and Mariah's superior range.
you know, I just realized that DONNA SUMMER is also missing. Ignoring this woman's vocal power (which is still as strong as it was in the 1970s) is blasphemy.
My vote isn't going to someone who sings ballads the best, otherwise it would be Mariah/Whitney. It's going to the person who only releases ballads,except for that 1 single that didn't perform as well as her ballads, and over 85% of her albums are of them.