6. Darth Vader - Star Wars Episode V: The Empire Strikes Back
And now we're back to some classic physical harm for Darth Vader's cruel dismemberment of his own son's hand in The Empire Strikes Back, slicing it clean off during a lightsaber battle, moments before Vader drops the bombshell that, yes, he is Luke's father after all. I think that pretty much clinches it; graphically mutilating your own son moments before you reveal yourself to him is not a great way to foster fruitful relations between the two of you. Aside from being a deadbeat for most of Luke's young life, to then start assaulting him the second he comes into your life is exactly what not to do. He was probably better off just staying away altogether, to be honest.