The candidates are:
Robert Baratheon: sired 16 bastards and pretty much took no responsibility for them (except Edric Storm). Should be held responsible for the abomination that is Joffrey Baratheon (although Joff wasn't his true son).
Jaime Lannister: doesn't seem to love his three kids at all. Though I suppose you can't blame him for it as the kids themselves did not know he was the father.
Balon Greyjoy: is a real prick towards Theon when they meet each other for the first time since Theon's went to Winterfell
Tywin Lannister: no explanation required.
Randyll Tarly: sent his heir to the Wall
Eddard Stark: perhaps a surprising inclusion. But I know that some people don't have a high regard for his skills as a father so I've added him here anyway. Didn't really do much to save Lady or defend Arya in the incident with Joff. Should have probably dealt with Sansa differently in KL.
Jon Arryn: should have kept Lysa well away from Robert.
Stannis Baratheon: doesn't show a lot of love for Shireen. Gives her a somewhat disturbing playmate.
Hoster Tully: raised Lysa.
Other nominations: Walder Frey, Roose Bolton and Doran Martell.
Edit: Clegane Snr. (as nominated by various boarders on this thread)
Edit: feel free to nominate others as appropriate
As a side-note: IMO best dad in Westeros is Davos Seaworth (OK so he's a smuggler, but he's a nice smuggler...)
Edited by Paxter, 29 June 2008 - 09:33 AM.