Tell me which one

I think crimson is the worst one out of All of them

Unfortunately you didn't show Peter and Lois Griffin who seem much worse than these

Well, all of them, they're all pricks.

As for who's the biggest one...I'd say Crimson. The others at least don't want their children to die from what I read. Crimson abused Moxxie for years, made him see that he killed his mother, molded him into a hitman (if a moral one), never bailed him out of jail, forcefully married him off to his creepy ex, threatened to kill him, and now seems to be ready to fulfill that threat.

All of them, including Butters parents, Ozai, the scientist from Fullmetal Alchemist and Hulk's dad