I recently reread American Gods, and it was just as wonderful as the first time. The premise is a fascinating one -- for tens of thousands of years immigrants to the Americas have brought their gods along with them, and these gods thrive or not depending on whether anyone still worships them, or even remembers them. It's a concept Gaiman has written about before, most notably in the Sandman comic storyline "Season of Mists." Here, the old gods, led by Wednesday (the American version of Odin), prepare for a battle against the new gods (Media, the Intangibles, the Technical Boy, and so on). Shadow is a human who is hired by Wednesday to serve as his bodyguard, but of course Shadow turns out to have his own, significant, role in events. Given the topic, faith and sacrifice are important concepts in the story, but Gaiman also has a lot to say about colonialism and the history of the Americas.
As with most of Gaiman works I read the novel with my laptop on one side of me and the Dictionary of Ancient Deities on the other side, the better to research every little scrap of folklore and history Gaiman seeds his work with. American Gods is a fun story in its own right, but I also loved learning about different mythologies, particularly those I had little experience with.
I read American Gods the first time right when it came out, the summer of 2001. Reading it now I can't help but put it as part of the pre-September 11th landscape. The resolution of the war between the gods had a profound, if unseen, effect on the America of the novel, and the last chapters of the book mention the sense of hope and renewal, the idea of limitless possibilities for the people in this hemisphere. Knowing what would happen just a few months later makes this section of the novel profoundly bittersweet.