Messerschmitt Bf 109
Made by Messerschmitt, it first flew in 1935, and was used by the Luftwaffe during the Spanish Civil War and throughout World War II.  It was one of the first modern fighters of the time. It had an all-metal construction, a closed cockpit, and retractable landing gear. It was powered by a liquid-cooled, inverted-V12 aero engine.