Exhale from Output is the most amazing vocal engine I have ever heard! Highly recommended! Requires Kontakt 5 or Kontakt Player 5.
Iris2 from iZotope has four sample layers, a unique spectral filtering and powerful modulation. An impressive 11GB samples and factory presets are included.
Vocalize from Heavyocity contains 4GB of vocal pads and phrases. Requires Kontakt 5 or Kontakt Player 5.