I've been ranking U2 as my number one band for fifteen years - not just my number one, but the number one, period. I'm a habitual analyzer, and I thought about the question to a point beyond excess. And like a true believer, I proselytized. Several years ago a friend of mine threw a party where none of the guests knew one another. Each person was asked to write a word or phrase on a nametag that would sum up who they are, and when I couldn't think of anything, my friend grabbed a marker and wrote "U2." And I didn't argue.
When I was thirteen - around the time I got into U2 - I didn't know much about music. I loved bands that I have since come to dislike, bands like Jefferson Airplane, Soul Asylum, REM, the Dead, the Doors. As I grew older and I learned more about music - and as I was introduced to jazz and classical music - I came to recognize that U2 were actually quite medicore from a technical point of view; but even then, as my tastes and my education expanded, my love for the band never wavered. U2 for me were always been the band in which everything came together in a way that it never did in any other group. Sure, Radiohead might be better in some ways; Pearl Jam might be superior in others; but they were all missing something that was more important than what U2 lacked.
The thing is, now, at twenty-eight, when the most formative years of my life as a fan should be behind me, I find myself questioning that view. And I find, to my amazement, that the whole idea of ranking leaves me cold. I just don't care anymore. I care about perfection; I just don't care about ordering.
There are three bands who to me stand apart from all others: U2, Radiohead, and Zeppelin. Past that, I could give you a list of artists who move to me wonder and tears, but no one really wants to read other people's lists - or at least, not my lists. So, to answer the original question, U2 are not my number one, but no one else is, either.