As I said in the 80's thread, I'm a die-hard fan. Bono is a god.
People seem to think they went too commercial since Auchtung Baby. But when you think about the whole Pop-Mart tour thing you can see their clever use of irony. It's as if they became commercial so they could make fun of commercialism. Otherwise they would have just been making fun commercialism and commercial groups and people would have called them assholes. So in this way the were making fun of themselves in order to say something about the larger concept of commercialism.
I also like a band that has enough artistic ability to re-invent themselves every now and then. They invented a whole new sound that may have taken older fans some time to get used to but it also attracted new fans. Then with their latest album they sort of found a happy medium between the two.
I never liked Madonna until her Ray of Light album for the same reasons. She has re-invented herself as an artist several times over.
That's better than old ass farts like The Rolling Stones who still sound the same as they did 200 years ago!