Polikarpov U-2 "Kukuruznik" (1)
Also known as Po-2, the "flying corn mill". I have a small "Soviet streak" because I realized how many characteristic WWII-era planes I am still missing. Although this one pre-dates the war, it was extensively used during WWII in various utility roles. Did I mention that with over 20000 built, this is the 10th most produced aircraft in the world?