At first, before MMA became mainstream, it was Vitor. By far!
He had the issue with his sister, and he was married to a top model who was (at a time) very very famous.
But once it exploded and the UFC started making events in Brazil, then Silva was ruling it.
By the time AS fought Vitor, it might have been close, but the kick to the face put Silva ahead of everyone.
Now I do not know. I think now it is more diverse... Maybe Aldo (since he is the only champ left) or Machida are the most popular...