Mine would be the Savatage/Nevermore tour, which took place September 12 2001 in Tempe. The whole mood was pretty funky immediately following the destruction of the Twin Towers. If nothing else, it was really weird looking up and seeing no planes or jets of any kind in the sky. The gig went ahead, and after a long wait to get in, my several companions and I proceeded to obliterate several shots and beers and settle in for the metal. Nevermore's performance was pretty killer, and midway through the set, Warrel pointed me out as I was wearing a Death t-shirt and dedicated "The Heart Collector" to Chuck. A lot of what made both Nevermore's and Savatage's performance particular good was that it was a bit more cathartic than might normally be the case.
But the true moment was afterwards. A friend of mine, Heidi, was an old-school metal fan who knew Warrel back from Sanctuary Days and had apparently been VERY closely aquianted with Johnny Lee Middleton of Savatage. After the show all the band members were hanging out, talking, Heidi getting cozy with Mr. Middleton, myself and Charlie talking with Jeff and Warrel about their performance, Chuck's health, politics, and Kernon's production versus Sneap's and why Emperor ruled. I actually recall Warrel hugging me. (This was before he quit drinking, we can't hold him to responsible).
Not particularly metal, but it stands out.