Firelord Ozai. Goku at least loves his kids and takes care of them, or at least tries to. Ozai banishes his son after disfiguring him and discards his daughter when she no longer of any use to him.
My money is on the dude that scarred his son's face out of pettiness.
Goku isn't the sharpest crayon in the box, but at least he TRIES to be a good person, not to mention saving Gohan's life on several occasions. And regarding leaving Gohan to face Cell, he was RIGHT, Gohan WAS the only one with enough power. And CELL was the only one strong enough to make him use it; sparring with Goku, he was able to hold his own without going NEAR his true potential.
Any argument about how bad a father Ozai is is only half formed if it doesn't address Azula. Yes, Ozai disfigured his own son and exiled him with an old coot everyone thought had more Bat sh*t than the cave floor.
Now look at the child he DIDN'T throw back. A fire bending prodigy who only knows how to related to her "friends" through fear and bullying, and who eventually devolves into paranoia (and possibly full blown hallucinations)when that world view of fear being able to rule everyone is proven incorrect. The girl is a sociopath at BEST.
Yes, I'd call CPS on Goku, but he does it because he's a drooling idiot.
Personally I love anime of all kinds but especially Japanese anime and even then I would say the majority of the series that emerge from Japan are a load of rubbish, hence I wouldn't pretend to know who is the worst father out of Goku and Ozai ;) Perhaps Dan needs to see some of the classics/greats and maybe something the length of a film would be easier to digest than a whole series :) Here's a few suggestions and please, everyone, feel free to add your favourites or anything you think I've missed:
Akira (of course)
Ghost in the Shell (1 & 2, although 2 only for the artwork really)
Ninja Scroll (pure awesome)
Nausicaš of the valley of the wind
Castle in the Sky
The Castle of Cagliostro
There's many more I'm sure but those are my favourites I can think of right now.
Also, on a side note, I'd always recommend seeing Japanese anime with the original audio since the voice acting is usually 10 times better than the dubbed over versions.
To be fair, Avatar is barely anime.
Am I the only one that can't get this one to play? I have the same problem with a couple Jimquisition episodes too.