Diana Wynne Jones is hilarious.(Potentially relevant link)
I love pretty much everything Diana Wynne Jones has written, but I never understand the review snippets they put on the books. 'Laugh-riot'. 'Uproariously funny'.
I'm not sure that I've ever laughed while reading her books. They're amusing at times, but do you really laugh out loud when reading them?
To my mind, Gordon Korman is funny and Diana Wynne Jones is just brilliant. Explain how Jones' funny. I want to understand. Show me a line or a scene from one of her books that made you laugh aloud.