Jason. His biological father is a non-motivation once we get past the original Two-Face confrontation, but like Cass he goes on a quest to find his mother. "Are You My Mommy" stories seem to end badly for the Batclan. Not sure where I'm going with that, but it's interesting to note that parents are at best a secondary motivation for Jason to be Robin.
As for Huntress, she's standing at the intersection of Bruce's and Cass' motivations; she wants to save her parents, but she's angry at them.
Cass is kind of an anti-Batman in that she does what she does in spite of her parents That's a very good way of putting it.