I was actually reminded somewhat of Elizabeth Bear's Blood and Iron when I was reading it, because there's similar elements going on in both books-- myths and legends and old gods are in ur base puppeting ur d00dz, with the impending Battle Royale With Cheese drawing closer with every chapter, and so on. And yet, I liked American Gods much better. I'm pondering, though, if part of the reason I preferred Gaiman's book is related to the reasons I much preferred The Vision of Escaflowne to Neon Genesis Evangelion, and part of the reason I preferred Escaflowne is because the protagonist is much easier to believe as a character.
Also, Gaiman's book had the sort of stuff in it that makes me like Stephen Sondheim and Terry Pratchett so much when they're at their best-- their stuff is about stories and how they whipsaw around and catch you where you least expect them. Stories are alive, and they are not tame.
Now, all that being said, I have to wonder... Is the difference between Mr. Nancy and Low Key Lyesmith one of kind, or one of degree?