Berklee College of Music, the Damnation tour with Porcupine Tree. This particular live performance rated second on my all-time list of best sound production I've heard live. Santana at the Cape Cod Collesium (Massachusetts) in 1978, to this day, still ranks as the most spectacular sound I've ever heard live.
The loudest ever for me was Damn Yankees and Ted Nugent at the Tweeter Center in Mansfield, MA. My wife and I were sick for three days afterwards. That was the last time I did not bring ear plugs to a concert (not that I've used them every time - I didn't at Opeth yesterday).