I have quite a few :
Rush - Vapor Trails tour in Toronto.
It was so good to see them 'home' (I'm from Montreal) after such a long absence. It was an outdoor concert, and in the background we could see the CN Tower, with the moon above it... a magical night to say the least !
The Tea Party with The Montreal Metropolitan Orchestra
Man, that was such an intense concert. The arrangments were very poignant, the choice of songs excellent... hell, I had tears in my eyes during a few songs in the show !
Pink Floyd - The Division Bell Tour
Pink Floyd is the first prog band I discovered (i was 5 or 6 years old), and this show was the only one I saw from them...
I could go on and on, but these are my most intense concerts.