UPDATE: Round 3 is now going on.
See Round 1 here.
Apart from having a big hand in different iterations of the Masters of Evil, I chose Baron Heinrich Zemo (the 12th Baron Zemo), in particular, because he was the first to show up in the comics; however, after thinking through my prediction more, it seems Helmut Zemo (the 13th, Heinrich's son) would be a better fit for the storyline and how the MCU seems to be shaping up. Nevertheless, this casting could be for either of those, in theory.
So let the voting continue with our winners from round 1 and a wildcard thrown in for this round.