What is the best concert you've ever attended and why?

Inspired by @PandoraBoxx’s recent question.

Mine would have to be a toss up between my first Tool show and my second Fleetwood Mac show. The first Tool show because a) it’s Tool, and b) I was just awestruck with the music, the art, the ambience. My second Fleetwood Mac show because it was the greatest hits tour and I danced, sang, and spontaneously cried through the entire show. It was also emotional because the first time I saw them was in 2003… with my dad who passed away 2 years ago. So, I was thinking of him the whole time. He loved Fleetwood Mac.