A KVR user has started to compile a spreadsheet of choir sample libraries that might be helpful if you're looking for such a thing. And aren't we all?  
 
The spreadsheet: 
https://docs.google.com/spreadsheets/d/1Ur4QfRANVyy6pjqfezd7D_2aVw4GDCFk3f07pxwd1E0/edit#gid=0
Yes, it's a little thin at the moment, but it's a work in progress.
 
The KVR thread: 
http://www.kvraudio.com/forum/viewtopic.php?f=42&t=420351
 

Thanks Bit.

Me likes my Soundiron Olympus.
 
Only played with my EWQL choirs once but they did sound nice.
 
I have Reali's Blue but have not gotten around to even trying it out. New job - bleh. I wonder if that even qualifies for the list.
 
Miroslav is dead to me as I will NOT be upgrading to ST3. Will that even go on the list? 

I probably only have simple needs though.

I had a piece once where I wanted really big choral oohs and aahs, so I threw in every sample library I had that featured choral oohs and aahs. I thought it would sound cool, or at least be an interesting experiment.
 
When I started balancing them all in the mix, some worked better than others and I started lowering the ones that didn't fit so well. By the time I'd brought the Kontakt libraries and Omnisphere down and down some more, only one instrument remained to carry the bulk of the oohs: Miroslav. Yeh, it beat out Omnisphere. It didn't sound as good soloed, but it fit the best.

Yeah Dave, but how many accordion based punk songs does the world really need?

bapu
Yeah Dave, but how many accordion based punk songs does the world really need?

If you're Weird Al, there's never enough.