The Unforgettable Fire the peak of creativity for U2, really? While a great record, it really was the album that showed that they were not going away soon, there is some classic stuff on it. But Achtung Baby was light years ahead in their growth as a band. There is not one track that sucks on it. They got really weird on Zooropa & Pop, but rebounded well since.
I have seen them 5 times so far, really one of the best live shows you can see in rock music. I was at shows in Chicago '06 Vertigo tour DVD release.