I used to find the "core J2ee patterns" useful because it covers the whole picture of a web application. (see here: http://java.sun.com/blueprints/corej2eepatterns/Patterns/index.html
However, these patterns were designed in 2002 (or earlier). So I am a bit reluctant to read them now as I do not want to get stuck in old technologies. (I want to move on to JSF and AJAX)
Out of the 15 patterns described there, which ones do you think are still useful? which ones are outdated or not useful for JSF/AJAX?
Service To worker
Transfer object assembler
Value list handler