Elements of statistic learning is one of the most important textbooks on algorithm analysis in the field of machine learning. The authors of this book, Trevor Hastie, Robert Tibshirani and Jerome Friedman, are pioneers in the area and have done really brilliant work. I consider this book as an important contribution that will definitely become a classic.
I recommend this book to graduate students in related fields like machine learning, data mining or statistics. Even though this is a wonderful book, I have to say, since all the authors have strong statistical background, their viewpoints can sometimes (if not very often) NOT be appreciated by the readers from some other fields. Many computer science students claim that the readability of Bishop's book is better.