Right off the top of my head? The one and only Karen Carpenter.
Don't have a favourite Carpenters track, so I picked one at random :)
Oh, well, in that case you really need to check out the center-channel SACD rips - her voice is just stunning!:
Don't know why I haven't noticed her before, but just saw Louise Marshall on a re-run of 'Later... with Jools Holland':
Róisín Murphy (of Moloko)
Thanks for the link. Just checked the videos out, well one of them anyway. The first doesn't seem to be available anymore :( I agree Karen's voice is spectacular :)
Edit: In reply to Mython. I don't go on forums much :P
Song:Acrobat (Album: Half Way Home)
this song is amazing, her voice is haunting and ethereal, sends shivers down your spine
Pitchfork gave her new album an 8.0
she just did a performance on KCRW and it was awesome! cant wait until she puts out a proper album.