Steph all the way. She had a couple of advantages. She was written to be a fun character. I defy anyone to remember a Babs story that stands the test of time before the killing joke. Cass was grim and I didn't like the way she could not talk or read, yet Bruce did nothing about it. Jerk move Bruce. Also Steph Batgirl also had the advantage of being written by one author, so no "genius" would decide to put his/her spin on the character. Do not get me started on Simone's Batgirl. It is grim and dark and no fun. Heaven forbid a comic be bouncy fun and charming. Also evil brother and mom who. Fled evil bro and left her daughter alone with said psycho? What kind of sense does that make?
Or I could be wrong.