#1 Kazuchika Okada

While the debate on Twitter was between Will Ospreay and Seth Rollins, it is still The Rainmaker and current IWGP Heavyweight Champion that stands on top. Okada hasn't had a bad match for years, and given the amazing main event style he's become famous for in New Japan, it's hard to argue that he's the best in the world today.
His 2019 hasn't been quite as good as The Aerial Assassin, but given the resume that New Japan's top guy has put together over the past 5 years, he'll likely be on top for some time. The debate has been between Omega and Okada for the past 2 years, especially with their incredible series of matches, but Kenny has been way too inactive in 2019. While Okada hasn't been as active as Ospreay, he's still just as good, and the G1 is another great chance to prove that.