I found the Dragon Book quite dull, and old fashioned. "Implementing Functional Programming Languages" [1] by Simon Peyton-Jones makes a much more interesting read.
Edit: I guess, we are talking about different Dragon Books. Wikipedia lists [2] at least three. And says about the first: "Principles of Compiler Design is now rather dated [...]."
[1] http://research.microsoft.com/en-us/um/people/simonpj/papers... [2] http://en.wikipedia.org/wiki/Dragon_Book
Compilers: Principles, Techniques, and Tools by Alfred V. Aho (Author), Ravi Sethi (Author), Jeffrey D. Ullman (Author)
http://www.amazon.com/Compilers-Principles-Techniques-Alfred...