Cassandra Cain is unique in several ways; she not only starts off completely mute, but also illiterate. This does not stop her from kicking butt, though.

She has a great father-daughter relationship with batman, and an almost mother-daughter one with Oracle.

She is by far my favourite Batgirl, but this fell one star short because of the storytelling being so choppy. This book is a compilation of all the comics, and it seems like all the comics were written so that if you missed one, it would not matter much. This might just be me, but I like a longer storyline.