I've gone through the GOF book, and found it not useful. I've gone through the Head First Design Pattern book but found it a bit outdated and the humour they tried injecting to complicate the examples.
I find it really useful the examples you guys use, the brevity of the contents, the organization of the design patterns (creational, structural, and behaviour), and the compare/contrast of similar design patterns.
Excellent, excellent work.
Calgary, Alberta, Canada