This one is my favorite, a 'cyclocopter':

https://www.youtube.com/watch?v=JoVmejDsMrM

It’s a really interesting project, worth checking out the video where he merged it with a companion computer to do computer vision tasks and inject controls straight into the flight controller https://m.youtube.com/watch?v=uaY2G5Kbj_g

Oh yeah, this'll scratch an itch.