Honestly... I kinda like PAMA. But like, Herobrine is a classic...

Ender Dragon.

PAMA is my favorite as i think he's the most dangerous villain in the game as he tried to make everyone "useful" and he plan to expand that to other worlds and who knows maybe the whole universe.

Arch-Illager, cuz Illagers need more recognition.

Also kinda off-topic, but I have no idea why so many people mistakes Illager with Pillager. It just triggers me.