I think u2.com is ok, it has alot of stuff, but sometimes it is hard to find what your are looking for, and some areas never seem to be updated. One official band site I think is very cool: http://www.pearljam.com
Personally, I don't think u2.com is a very good site, it just does not seem very well organized, but I do like how on the opening page there is a recent news section that you can scroll through.
Most of the band's websites I usually go to are for small bands, or new bands, so I think that U2.com is amazing. I'm sure there are better out there though, it kicks the crap out of thecure.com and radiohead's official site.
For an official site, it has a lot of stuff... all those exclusives and stuff are amazing, and it's also far more up to date than a lot of official sites. BUT the design is really not that great, and they could have sooo much more. I mean 30 second clips of the videos? come on! be like www.garbage.com and have the complete videos!