Stage presence is a big one for me. When I saw My Chemical Romance last year it was this big spectacle and just marvelous. Even though Gerard himself is not the best singer, it was just a fun time period. When I saw Slayer with Testament, Behemoth, Lamb of God, and Anthrax. It was the mood they created. The intensity was something you could literally feel from just the noise. They were really giving it their all as it was Slayer's farewell tour. But the crowd also kind of matters too.
And when concerts have disappointed me, it's usually been because the stage presence is okay at best but the audience has been terrible. There were some local hip-hop/rap festivals I would go to. And the bigger the festival got, the more belligerent the behavior got. You would have people pushing and shoving to get to the front. And since these festivals were always in the middle of summer. It was be unbearably humid. Then they switched to a venue that was all concrete and that just killed my knees entirely to be there for 5+ hours.