Mr. Bennet is definitely one of the most humorous characters in the entire novel. It is also clear that he loves Lizzie Bennet very deeply, and that Lizzie herself is attached to him. However, when we consider the question of whether he is a good father, the text is not sparing in revealing his failings.
For example, in spite of Lizzie advising him strongly against it, he decides to give Lydia permission to go to Brighton. As he himself admits afterwards, the ensuing tragedy is of "his own doing." However, he does have the humility to admit he was wrong and to praise Lizzie for her foresight:
"Lizzie, I bear you no ill-will for being justified in your advice to me last May, which, considering the event, shows some greatness of mind."
We can also find other criticisms of his character in the letter that Mr. Darcy writes to Lizzie in Chapter 35. When she reflects on its contents in Chapter 36, note how she comes to agree with his thoughts of her father:
The situation of your mother's family, though objectionable, was nothing in comparison of that total want of propriety so frequently, so almost uniformly betrayed by herself, by your three younger sisters, and occasionally even by your father.
However, above all, his role as a father is shown to be bad by the way that he constantly exposes their mother to ridicule in front of them and by the way that he had not laid aside any money in case of emergencies, because he had been hoping for a boy that could inherit Longbourne. Thus, although witty and amusing, unfortunately we have to come to the conclusion that Mr. Bennet is not a good father.