Let's deal with it, the vocoder. The real deal with cool vocoder tracks and not the lame auto-tune stuff - they're two (three including the talk box) very different ways of voice treatment that fart too often is confused as being the same.
There might be traces of auto-tune in a few tracks, but in combination with a vocoder. Regardless, they're great songs, even when they sound auto-tuned (despite of the fact that a vocoder actually was used).
This playlist is of course including Kraftwerk, as well as lots of classic rap/electro rap and some of the vocoder loving electro artists/bands of today (France anyone?).