I don't know Dragon Ball Z, so that's the main reason I pick Ozai.
Rarhnor said:
Ozai, while incredibly mean and downright evil to his own son, takes care of his other child Azula. Sure, Ozai is a bad father to Zuko, but not to Azula whom gets pandering and encouragement from him.
I'm afraid I don't agree that Ozai is a good father even to Azula. He doesn't care about her either, he uses her because he knows he can.
The only reason Ozai pays any attention to Azula at all, is because she is a Firebending prodigy, something he can use for political and military ends.
So , while his wife was making sure their son was getting any love at all (Ozai wasn't going to waste time on a son that he had no use for), Ozai decided to "pick up the slack" where Azula was concerned, by encouraging her manipulativeness and cruelty.
This way, she was loyal to him (as far as she's concerned he's the oly one who "cared" about her: i.e. paid attention to her) and she grew up to be an excellent strategist, political schemer, and a Firebending master, who did everything Ozai told her to do.