I've been cyber-shopping for a good vocoder and last night I stumbled upon Klanglabs Vokko, a VST vocoder plugin that can be controlled in real-time in Ableton Live. Before I continue, let me just say that over the years I have used the Akai Vocoder, Waves Morphoder, Orange Vocoder, and the one built into my outboard effects processor with shitty results. So like I was saying, I found Vokko, installed the demo, loaded it up, and WOW! I was impressed not only with its clarity and control but also the fact that I was able to control the carrier synth in real-time! The demo is a little limited (primarily no control over the filters) but fully functional nonetheless. To overcome the fact that it only ships with one soundfont, I obtained this distorted saw lead soundfont and added the Scarbee Vintage Keybord FX to the channel (using the Tight Funk preset) and it really brings Vokko to life.
To purchase the full version it's only $20.00 but to be completely honest, I think the demo (Vokko-Lite) would suit just about anybody's needs. If you're looking for a nice 'coder...check out Vokko and just incase you're not sure on just what the hell a vocoder is, read this.