Ronald Reagan was the best president the country has had in the modern era.
Adolf Hitler* was the closest thing the world has probably had to the Antichrist, although who the actual Antichrist is, we have no idea, and he may not even exist at all, nor ever exist.
*Genghis Khan is also a strong contender.
The Beast depicted in Revelation was almost certainly meant to be interpreted as a Roman emperor.
I'm sure people here know this but the gematria (Hebrew numerological value) of "Neron Kaiser" added up to 666, and the clincher for its identification with the Emperor Nero is that the variant 616 found in early manuscripts resolves to "Nero Kaiser", his Latin rather than Greek name. It makes sense because not only did Nero traditionally order the first state-backed persecution of the Christians, but there was also a "Nero Redivivus" legend that the dead Emperor would come back and rule again.