Ozai is the worst...anything...he screwed up his whole family, especially his kids. I mean Azula?!?! And Zuko has a permanent scar from his evil insanity...Ozai was nothing but evil...not a shred of good in him, and I don't feel bad for him, at all. He screwed up his kids just so he could be more powerful and controlling of them.

Yakone was batsheiss insane and did make his kids do bad things all in the name of his revenge, and he really, really messed up Noahtak and Tarrlok, but I dunno if he's worse than Ozai, I can't imagine anyone more horrible than Ozai.

Sato, well...he was a confused dip and a jerk, but I think he still had his daughter's best interests at heart, he wasn't just in it for himself.

Ozai was a horrible father, and everything Roxas1314 said is true. Sato wasn't a bad father for his child, but more like a bad role-model for Asami.

Now last but not least, Yakone. He made his sons learn and bloodbend each other. He made Noatak go on his quest for Equality, and in the end, his actions lead to the death of his two sons.

Yakone & Hiroshi are bad, but I believe that some part of them still had some emotion or love for their children, but Ozai, he felt nothing for Zuko or Azula, I'm sure of that.

Ozai is the worst, despite having the sexiest voice on the planet.

While Yakone was an awful father (at least when he found out about his children's waterbending), he did care about them in his own way. When Noatak ran away, he gave up on his revenge schemes and wasn't the same. He even went looking for him even though he disobeyed and bloodbended him. He was a decent father in what Tarrlok described as "the good years." He was so caught up in his revenge plots that he didn't realize how deeply he was affecting his children until it was too late.

With Ozai, he didn't have any guilt for what he did to his children. If Azula were to run off like Noatak did, I can't see Ozai chasing after her, he would probably try to replace her. He burned Zuko for such a small offence, then banished him just as he was entering adolescence to look for the impossible. Basically he was saying "don't come back." And if Azula didn't lie for him when they got back, he wouldn't have treated him as well as he did. He was perfectly okay with the idea of killing Zuko, and mockingly talking about what happened the night his only loving parent disappeared. As for Azula, he used her for his personal gain (Yakone did the same, but I think he felt guilty in the end. Ozai didn't feel guilt, and he used her over and over again.) He turned her into a soldier to cast into the world in hopes that she'll bring success to the Fire Nation in life threatening missions. And in the end, he got what he wanted and shoved her aside- giving her the title of Fire Lord which might have even been useless. He just didn't feel any real affection for his children, or anyone else for that matter.

As for Mr. Sato, he was a good parent until his hatred and grief overcame him. Even when he tried killing Asami, I feel like he thought she was brainwashed and beyond help, and that he was going to "put her out of her misery." -Of course, that doesn't exactly make you a good father.

All of them!

I thought about it a lot and I realized the worst act a father can do for his children is to try to kill them :/

SATO=the most horrible father in the WORLD! he lied to his only daughter for years! he almost kills asami and to top it all off he made every weapon the equalist had!

Ozai the worst then Yakone. Hiroshi's bad but not as bad as these guys

They are all prety terrible.

Hiroshi did turn against his daughter in the end, but he orgionally did love her.
Ozai felt nothing for his kids at all, but Yakone tried to use them as his weapons. Even if what Ozai did was awful, it helped Zuko become a better person in the end (Azula was just pretty screwed up from the start). Ozai abonded his kids, but Yakone was using them for his revenge, abusing them.

Horrible!!!

I don't think I need to point out all the bad things Ozai has done, even as a father, not just a ruler, to prove he's a crappy one. The facts are out there, and it's all true!

He scarred Zuko for life.......literally