My 2001 Garden Results
It was in 2001 that I first became seriously interested in growing giant sunflowers.  It was a 12 foot Skyscraper from Ferry Morse that got me hooked on giant sunflowers.  In previous years I had mainly grown ornamental sunflowers and some mammoth russians, but I never seen a sunflower as impressive as Skyscraper. 
(above) The tallest sunflower of the 2001 year; 12 foot Skyscraper grown in New York. 
More info on Skyscraper

  (left)  A 9+ foot self sown sunflower in my backyard in NewYork.  I'm not sure exactly what this particular plant crossed with, but it's multi-branching.
(above) A row of Kong Hybrid sunflowers grown in my driveway in New York.   Although they weren't very tall, many had massive stems and leaves.
More info on Kong Hybrid

(left) A 10 foot Giganteus sunflower grown at my relative's house in Pennsylvania.
More info on Giganteus