I could claim it was a close-run thing but the truth is that, to possibly no one's surprise but Diablo's, Dr Doom ran away with it, coming out on top with a crushing nine votes.
In second place was the Sub-Mariner, with just two votes, while Galactus had to settle for a mere one vote.
Not to be outdone, Hockey Stick Head matched Galactus stride-for-stride by also getting one vote, meaning Hockey Stick Head is officially the joint third-greatest Fantastic Four villain of all time.
No I don't know who he is either, and neither do Mr Google and Mr Wikipedia, but a good villain never let a small problem like non-existence get him down.
As always, thanks to everyone who voted.