Best female vocal recording on CD?

i am a sucker for great warm rich smooth female vocalists, especially on tube gear and speakers that image well. but i am almost always faced with a great voice/song but a sonically inferior recording (examples too numerous to list) or a great recording of a mediocre voice.  rickie lee jones (pop pop) comes to mind- fab recording, but come on lets be honest about her voice. however, i will almost always pick great recordings and leave the bad recordings for the car.

 so i am asking for what you use as a reference female vocal recording/track. right now i come back tp bonnie raitt "you cant make me love you" from luck of the draw.  big, warm, strong voice. not a perfect recording. but hmmmm that voice.

my only requirement is it has to be on CD. and we all know of great vinyl that did not translate into great CDs.  so help me out here, what should be my next music purchase 
Oh yeah, Mary Gauthier is a fairly new discovery of mine. I have a couple albums of hers, still have to get the one produced by T-Bone Burnett.
Ok, I’ve come back with new discoveries, I think you need a female voice, a piano playing, and your ears to listen to these 2 songs to complete a story and journey on your own, note that the recording is not available on YouTube, you can try download somewhere else:

Akiko Yano (矢野顕子) - 中央線
Akiko Yano (矢野顕子) - Prayer

 What surprises
s me is how many of these artists would be on my all time list too. That includes artists I would think were less well known, like Sarah Jarosz. There are some omissions, I would think would be on a lot of peoples lists, some very well known.

 Jennifer Warnes, "The Hunter"

 Sara K, "Waterfalls" (Just wonderful recording, on Stockfisch)

 Shawn Colvin,, "Fat City", "All Fall Down", but any really

 Kate Rusby "Underneath the Stars", "Hourglass", but again          

                      anything, a great English Folk singer.

Jonatha Brooke  "10c Wings"

 Two observations on this thread. Firstly, aren't we fortunate that there are so many great female vocalists around. All the way through this thread, I have been thinking, "Oh yes, I forgot her". There are just so many around, most of them never get played or listened to, in our world of compressed Pop and manufactured artists, boy bands, TV competition winners.

 Secondly, how separate most countries are, in terms of music availability. Many of the US artists mentioned I have not heard of and when I look on Amazon, are largely unavailable, or cost £50 a CD. Yes I know with Tidal, Spotify etc, so much more is available to us, but what if you want the physical discs?

So many great suggestions here, many that I already enjoy and many more I've not heard. I just ordered 10 new cd's based on the suggestions here. I don't want to repeat many of my favs already mentioned but here are some I don't think I've seen mentioned here:

Lydia Loveless, Real
Connie Evingson, Gypsy in my Soul
Jeannie Bryson, Tonight I Need You So 
Jen Chapman, Open Wide
Haley Westerns, Pure
Diane Birch, Speak A Little Louder