I saw it staged twice, both times at La Scala.
The first time when I was a teenager, C. Kleiber conducting. I was with my grandma and unfortunately I cannot remember much of that evening
Then, some years ago, Daniel Barenboim conducting, Waltraud Meier singing Isolde. A Patrice Chereau's production.
I was thrilled from the beginning to the end, and particurarly during the liebestod when Meier/Isolde started bleeding as if the trascendent and unbereable grief had been leaving a tangible sign in her body.
In this video, at the very end someone in the audience just ruined everything. Luckily not in the evening I was there...