Assassin's Creed 2 was amazing. I view brotherhood and revelations to be extensions of that ( to varying degrees). Then when 3 came out, I didn't really like it that much. Even though I recognised some of the improvements made mechanically the game just didn't have the same magic imo. Black flag was similar, I saw it as a definite improvement over 3, but to me it didn't have that magic. Maybe I'm stuck in the past, or maybe the rapid release rate has left me jaded. I'll be skipping the next few and then I'll try it out again.