I have 3 special U2 shows and I can't choose between the three as they're all best in a certain aspect.
The first one is 9 May 1993, Rotterdam (the Zooropa Tour). It was my very first U2 concert. I was on the field, right in front of the B-stage. You know the spot where Bono jumps into the audience during UTEOTW? Well, I was just out of reach.
As a first U2 live experience, nothing can top that of course (even though a lot has faded in my memory, must be the sensory overload).
My second pick is 13 July 2001, Cologne (Elevation Tour). I had GA tickets (again) and this time my sister also came with me. It was her very first U2 show. We were at the venue early, hanged around all day and chatted with other very nice U2 fans. The doors opened, the rush was there and we ended up totally at the front right before Adam's glasses!
Needless to say this was my best Elevation Tour experience. And what a first show for my sister (not to mention that U2 were ON those two days in Cologne!)! It's almost three years later and she still talks about it sometimes, saying how great that concert was.
Suus
My third pick is the 5 August 2001 concert in Antwerp (again Elevation Tour). I'd gotten tickets through Propaganda. They were seats on the left side, halfway between the tip of the heart and the main stage. I choose this one because I thought this was musically the best Elevation concert I attended. Bono also sang some snippets of Two Shots Of Happy, One Shot Of Sad before and after Stay. Sunday Bloody Sunday was also very emotional (with references to a car bombing in Ireland) and New Year's Day was also really sweet as Bono picked two small girls from the audience and ran around the heart with them.
Gee, writing about this makes me again all excited about the new tour!
C ya!
Marty