Female Vocalists.

So, I'm sitting here, listening to Fiona Apple's Tidal, and I realized I don't have a lot of female vocalists in my library. Suggestions are greatly appreciated Giant Bomb Brethren!

Taylor Momsen from The Pretty Reckless is really good (she plays Jenny in Gossip Girl), if you don't mind heavier stuff, then The Letter Black is really good as well.

Here's a few off the top of my head.
 
The Pack A.D.
The Kills
Babes In Toyland
The Dresden Dolls

This is great! Keep 'em comin!

Florence + The Machine

@TheHT: I watched some live show on palladia on this band. She gets pretty crazy!

Again, heavier (and pseudo Christian) stuff; 
 
Flyleaf 
We are the Fallen (sound a bit like Evanescence) 
Fireflight 
  
Also the Sounds are one one of my favourite bands, their singer has an amazing accent, on other accents that get me all giddy, Lena Meyer-Landrut (last years and this years German entry for Eurovision), oh and of course Metric.

Katy Perry, Lady Gaga, Britney Spears, Glee?

She sang the avatar theme song and also FFXIII's song, if you don't like that, just get the new lady gaga cd.
 

@Inkerman: After youtubing The Sounds, i gotta say, I LOVE what I'm hearing! Thanks!

Garbage, Yeah Yeah Yeahs, like half of Broken Social Scene's library (if the song has any lyrics at all), Tegan and Sara, School of Seven Bells, Ida Maria 
 
Looking through my music library, that's about all the female vocal stuff there. Mostly rock/pop.

Yeah Yeah Yeahs

Phantogram

The xx

• The xx
• Yeah Yeah Yeahs
• Fever Ray
• Portishead

Adele

 
NIghtwish 
Delain 
The Gathering

@HitmanAgent47: That was beautiful. I won't be running to Lady Gaga. xD

@Underachiever007: Fucking LOVE Portishead.

Regina Spektor.

@EvilTwin: I learned of her through Ben Folds (You Don't Know Me), beautiful voice.

Lacuna Coil

• Florence + The Machine
• Imogen Heap
• Nemesea

@EvilTwin: Loving it. Listened to 'Actors Out Of Work', and 'The Strangers'.

the bird and the bee?
 
that's all i got

melanie fiona?  erykah badu?  chrisette michelle?  i dont even know why i just typed like that.  im not gonna edit it

Definitely Imogen Heap (don't forget her earlier stuff when she was part of Frou Frou)

Robyn

Missy Higgins (from Australia, no I didn't mean Missy Elliot)

Venus Hum

Feist

Sarah Blasko (also Australian)

Joanna Newsom (haven't listened yet, but heard good things).

A Fine Frenzy

(apologies for the spacing, not sure why it skips every other line.)

I've been a big fan of the voices of  
 
Hayley Williams from Paramore 
   

@the_OFFICIAL_jAPanese_teaBAG: Love me some Badu, also, Wake up was a lil meh. I feel like Legend could've brought more to the table. It would've improved the album significantly if Legend and The Roots recorded it live, in studio.

Alina Simone 
Amanda Palmer 
Anna Ternheim 
Charlotte Gainsbourg 
Deerhoof 
Dessa 
Emily Haines & the Soft Skeleton 
Esthero 
Holly Miranda 
Laura Marling 
Lou Rhodes 
Pascale Picard  
Santigold 

I just went through my library and these are my favorites. I have a lot more if you want em'. 

@Chop: Fuck yes, PM that shit homey.

and Ellie Goulding 
  

surprised no one mentioned norah jones yet
  

@weeman105

Metric

Fifth Hour Hero

missy elliott

CSS

Halcali

Marina and the Diamonds

Siah

and

probably the best female vocalists of all time:-

The Breeders.

She & Him 
  

There...  
 
I sent you enough to keep you busy for a year or so. 

Sia Furler has the most cathartic voice.

This is my favorite song from Florence and the Machine. It reminds me of my love. :)

EDIT: Oh, and I don't know who sings this (she's not a permanent part of Massive Attack) but she's absolutely phenomenal.

Regina Spektor, Rilo Kiley, Nellie McKay

Kim Deal.

Thread fucking over.

Chew Lips 
The XX 
Nouvelle Vague

I'm a fan of Within Temptation.

This is my favorite type of music. Hold on to your butts: 
          
Meg & Dia

Alison Sudol (A Fine Frenzy)
  

You gotta check out Adele, she got a very beautiful voice!