Celemony Melodyne - Celemony Melodyne is the perfect quick and easy tool for all your tuning needs.
TAL-Vocoder - Vintage vocoder emulation plugin in VST and Audio Unit format.
GSnap - With GSnap you can get an auto-tune effect.
ReSlice - Slice your audio with an advanced, rhythmic arpeggiator and FX.
Revoice Pro - Revoice Pro is an audio plugin used for vocal tuning, time correction and ADR.
Voloco - Auto-tune made simple and funny for everyone