The ME-262, the first jet fighter ever, but the war was over when it came out of the production line, it wasn't even reliable enough for service;
Lastly, the plane that never was (never put in production after the war was over), the Horten 2-29;
The all-wing Ho 2-29 looked more like today's U.S. B-2 bomber (B-2 bomber picture)—or something from a Star Wars prequel—than like any other World War II aircraft. Made primarily of wood and powered by jet engines, the plane was designed for speeds of up to 600 miles an hour (970 kilometers an hour).
Armed with four 30mm cannons and two 500-kilogram (1,100-pound) bombs, the planned production model was also meant to pack a punch.
A Ho 2-29 prototype made a successful test flight just before Christmas 1944. But by then time was running out for the Nazis, and they were never able to perfect the design or produce more than a handful of prototype planes.
Neither of them all.
The ME-262, the first jet fighter ever, but the war was over when it came out of the production line, it wasn't even reliable enough for service;
Lastly, the plane that never was (never put in production after the war was over), the Horten 2-29;
the last and only surviving Horten;