Robotronic:
http://www.kvraudio.com/news/5123.html
Pretty nice sounding, lots of features, although you wont be able to use the built in synth in Renoise, and it seems a bit CPU heavy.
Orange Vocoder:
http://products.prosoniq.com/cgi-bin/regis…l&refno=31/
Old as the hills but still sounds nice, slightly tempremental maybe (you get weird spikes sometimes) and has quite a big latency, but I use it all the time.
IMO, the best VST vocoder I’ve ever used was the Steinberg one included with Cubase VST, unfortunately I can’t get this to work in Renoise because of this:
https://forum.renoise.com/t/vstfx-midi-receive-capability/20292