Found MDA Talkbox updated to 64bits alongside all their plugins which are now public domain:

https://sourceforge.net/projects/mda-vst/postdownload

I still urge you to give MDA Talkbox a try. Very easy to use, the main trick is to carefully choose the synth sound you send as a carrier. Simpler sounds greatly help to achieve a clear effect and intelligible lyrics. Square wve based synth leads work like a charm (don't forget to clear effects like reverb & delay for a clean signal). More complex and elvoving pad sounds are also a great asset to create neat and ethereal harmony lines.

The plugin being really low on CPU usage, feel free to use a good synth carrier for great results.

 

I like Akai Professional DC Vocoder.

 

I just tried this and liked it well enough that I went ahead and updated the Talkbox source to use double precision instead of single precision.
This is going to sound slightly different than the original and perhaps '''better''' (in a technical sense - you know what I mean).

I've uploaded the updated plugin with the modified source code and a binary for x64 Windows 10+ here:

https://app.blackhole.run/#1b42fbf1ff1wVxX9mpMasfttYN2qbhZiWZoSeXxcXk4

 

Reason Studios BV-X Multimode Vocoder. This thing is so awesome! FL Studio Vocodex sounds also very awesome.

 

Not yet tried (I'll do it next weekend), but downloaded. Thanks, thanks, thanks!

 

Behringer VC340 for the most classic understable vocoder IMHO.
Izotope Vocalsynth for the best ITB vocal effect possibilities.