I`ve seen many many gigs, but my all time favourite gig was when they did " A Crystal Day " at St Georges Hall in 1984.
The acoustics and the ornate splendour inside the Hall, was just made for them.
If I remember right, they did it as a one off for the Old Grey Whistle Test and you can still watch it on the likes of Youtube.
When the Gregorian Chant starts amongst all the dry ice, which is so thick all you can see are then silhouettes of the band and the Samurai dancers with the swords, alongside them, the atmosphere was that electric, you felt as though the crowd was actually lifting off.
I`ve never experienced anything like it at any gig I`ve ever been too and I was stone cold sober too !