TAL-Vocoder - Vintage vocoder emulation plugin in VST and Audio Unit format.
Omnisphere - Piano, pad and synth VST for DAW's.
ReSlice - Slice your audio with an advanced, rhythmic arpeggiator and FX.
Serum - VST for FL Studio, Ableton Live, and many other VST supported DAWs. Heavily utilized in EDM.
Voloco - Auto-tune made simple and funny for everyone
Nexus 2 - Nexus 2 is a synthesizing tool that comes with easy navigation columns, categories, presets, color tags, bookmarks, and other features, which makes it an easy-to-use but powerful software.