I adore Sarah Brightman, Idina Menzel, Katherine Jenkins, Lea Solonga, Judy Kuhn and Whitney Houston as all-time favorite singers... and I shan't forget Ruthie Henshall as well. I like Diana Krall as well, and also Amy Winehouse, and Duffy. I enjoy Duffy's voice - it's... interesting, to say the least.
There are others, which I might have forgotten. But I'm also just trying to keep this to classically-trained singers and jazz/blues singers, and not include pop singers (like Taylor Swift or Demi Levato, who can't really sing, to be honest.); besides, this is the Classical/Jass/Blues forum. x3