simply THE greatest band of all-time. they are generally regarded as one of the best, and they aren't even dead yet. that's saying something, lol.
i like stuff from all of their albums. generally, there are songs on each album to suit all tastes, and that's what i like. my favourite u2 era is the 90's, but that's not to say i don't like their output from, say, the last 2 albums, which Did contain some great music. yes, even the much-maligned HTDAAB contains some great moments.
I like the notion that they have never rested on their laurels, and to quote bono; "if it's interesting for us, it won't be bullsh*t for you either".
there has never been greater chemistry in any other band that i have heard.