hack// was ok but the show did not have enough action to drive the plot as compared to SOA. On the other hand SOA is more oriented with the plot by action strategy and unlike hack the main character in SOA has a higher chance of death. In fact the reality of death seems to be much more enforced in SOA which helps keep the audience attached to the focus of the story. SOA also uses this factor to then go out side and explain more about how people in general live though this by the use of side stories that we currently see. The most similar title to SOA I would actually say is Accel World which is from the same author.