My vote goes to the De Havilland Mosquito.
This aircraft is otherwise known as "The Wooden Wonder", due to it construction material.
Renowned for its speed and versatility, with the added powerplant the Rolls-Royce Merlin, the aircraft excelled.
Many versions were constructed allowing it to be used in roles such as ground attack, night fighter, reconnaissance. The first truly multi-role combat aircraft.
A masterpiece.