Ajax Design Patterns, by Michael Mahemoff, has been a pleasant surprise. Michael separates the hype and buzz from the technical reality behind building modern web applications and content.
He does a fantastic job exploring patterns that have emerged over the past few years in web development. The usual suspects are covered, but he also addresses alternatives (old and new) to the trends. His conveyance of relevant historical elements has been very useful and helps with the flow of the book.
If you like the masochism surrounding the Java vs. DHTML vs. Flash debate, there are constrasts and comparisons throughout the book, with relatively unbias perspective. As an old browser developer, of course DHTML/Ajax wins in my heart!
This book is not just a breakdown of acronyms and trendy frameworks. It has real flow and thought about the over-arching impact the techniques have on web apps. With that said, there are plenty of code examples and live online demos; its not just a high-level perspective either.