Agile Software Development: Principles, Patterns and Practices
2: Martin Fowler
Refactoring: Improving the Design of Existing Code
3: Mike Cohn
Agile Estimating and Planning
4: Mike Cohn
User Stories Applied: For Agile Software Development
5: Andrew Hunt , David Thomas
The Pragmatic Programmer: From Journeyman to Master
6: Alistair Cockburn
Agile Software Development: The Cooperative Game (2nd Edition)
7: Craig Larman
Agile and Iterative Development: A Manager's Guide
8: Kent Beck
Extreme Programming Explained: Embrace Change (2nd Edition)
9: Jim Highsmith
Agile Project Management: Creating Innovative Products
10: Paul Duvall, etc.
Continuous Integration: Improving Software Quality and Reducing Risk
11: Mary Poppendieck , Tom Poppendieck
Lean Software Development: An Agile Toolkit
12: Ken Schwaber
Agile Project Management with Scrum
13: Ken Schwaber, Mike Beedle
Agile Software Development with Scrum
14: Alistair Cockburn
Crystal Clear: A Human-Powered Methodology for Small Teams
15: Venkat Subramaniam, Andy Hunt
Practices of an Agile Developer: Working in the Real World
16: Kent Beck
Test Driven Development: By Example
17: Johanna Rothman
Manage It!: Your Guide to Modern, Pragmatic Project Management
18: James Shore , Shane Warden
The Art of Agile Development
19: Ron Jeffries, etc.
Extreme Programming Installed
20: Esther Derby, etc.
Agile Retrospectives: Making Good Teams Great
I think it's good to see that so many agile publications have made it onto the big list of software engineering books. Far more than any publications with "traditional" views (if there ever was such a thing).
So, if you were looking for some more interesting books on agile software development, you can stop looking for a while. These twenty are the crème de la crème!