Prusai 3
Electron i3
The http://electron3dprinter.com variant; it has some design glitches (mostly related to cable management, positioning of the Z axis probe and the Y idler being printed wrong - https://twitter.com/ze_m0n5t3r/status/656717244932554752), there is zero support and quality control is lacking, but it's nice and stiff and I printed 0.05mm layers with it without issues.