Besides the Straw Hats, the characters that seem to most frequently pop up are Law, Katakuri, Yamato, Carrot, Mihawk and Hancock. Sabo & Ace only appeared a couple of times and I've never noticed Shanks anywhere.
I've seen Shanks earlier today, but I don't remember in which zone. He was in 3rd.
–- Update From New Post Merge ---
Hancock is again 1st in North America. Otama is 3rd.
Shanks is 3rd in Europe.
Carrot is 1st in Latin America/Caribbean (it really feels like there's some campaigning for her there, she's always in the Hot 3)
Bentham is "the Mr. 2" in Oceania.
Jinbe is 1st in Middle East.
Damn, this new hourly updates made me addicted to the rankings, lol.