Pratchett wrote the majority of Good Omens and, in my opinion, most of the humour of the book came from him. If you want more like that you'd be better off reading Discworld, a generally delightful series.
Originally Posted by Harleyquiiinn
Gaiman is better at straight storytelling than he is at comedy. I enjoyed American Gods but I seem to remember finding his attempts at humour pretty clunky most of the time because of the otherwise mature tone of the book. He is good at the serious bits, and fine when humour is woven intrinsically into the plot, but struggles with actual direct jokes. At least, that's what I remember from possibly a decade (or more) ago.
I like Gaiman but Pratchett is far funnier and just generally more talented as a novelist. Gaiman's talents are...less specialized, perhaps. Which isn't a bad thing at all. It's just a different thing. I suspect Gaiman himself would agree quite strongly with this assessment.
“Today a young man on acid realized that all matter is merely energy condensed to a slow vibration, that we are all one consciousness experiencing itself subjectively, there is no such thing as death, life is only a dream, and we are the imagination of ourselves.” – Bill Hicks