Schlappi Engineering Three Body Black

While not a traditional complex oscillator, I believe that this module falls into that camp. Not two, but three digital oscillators are used to produce interesting cross modulation functionality.
What this means is that there is a huge variety of sounds that can be summoned by this module. While most of the online demos showcase the more noisy side of the Three Body, don't be fooled. It can also be very musical and sweet sounding as well. And despite being digital it also has an analog 'heft' to it.
The built quality is one of the best in Eurorack and the multitude of outs and patch points mean that you have worlds of sound at your fingertips.