I just noticed that someone nominated the Horten H9. In case anyone is wondering what that is, a guy at our club has built one - completely scratch built from nothing more than a 3-view.
As you can see, it looks incredible (even without the Luftwaffe colour scheme), but although he did some taxi tests this week, it is yet to fly (the grass at our field was too long and he wiped off the front leg of undercarriage)! I gather that the orginal prototype which flew in 1941 was a bit of a handful - so I imagine the model will be too! The model is pretty faithfull to the original - right down to the tricycle undercarriage, elevons, flaps and "drag rudders". The power comes from twin GWS EDFs driven by brushless motors - and I can tell you that twin fans sound much better than twin props!
Robin