Big fan of both games/series right here! Well, I love the original Arcade and Genesis/Mega Drive versions of Altered Beast - still play them to this day. I've played Bloody Roar and Primal Fury (or is it Primal Rage? It's the one on the GameCube). Long has and will always continue to be my all-time favourite character. My friend used to main the mole (cannot remember your name, sorry moley!).
The series supposedly went downhill on the PS2 - I was actually looking at picking up the later few games only the other week but poor reviews put me off. Did the series add any interesting new characters? I think they sort lost steam in Primal Fury/Rage when that Unknown character with the... thing transformation was introduced.