American Gods, by Neil Gaiman.
I'm not really sure what the genre would be. I'd prolly just clasify it as fiction, but you could make a case for taking that extra step towards fantasy, I suppose.
It's probably one of the best books I've read in the last few years. Basically, it asks the question "What happened to all the Gods people brought with them to America and then (more or less) forgot about?" An incarnation of Odin is one of the main characters. He was brought over with the Norse when they came to North America and has been here ever since, losing power as his believers dwindle. So, you have all these old Gods and folk heroes, non-human entities (Odin, Kali, Wisekejac, etc.) from old belief and religion. But now there are new Gods being born, like the Gods of Internet and TV, and there's a power struggle going on between the old and the new. In the middle of all this is a man named Shadow, an ex-con whose wife just died. He joins Odin and tries to gather the old Gods to help fight the new ones. The ending is a bit of a surprise, and the plot is really good, with a few side-stories that are pretty great. One of my favourite aspects of the book was trying to guess who all the old Gods were, because you're not really told outright for a lot of them. Also Shadow, like Neil Gaiman, is very sexy.
Also, kudos to whoever recommended Good Omens; it was the second one on my list, after AG. <3
Honestly, I'd recommend anything by Neil Gaiman or Terry Pratchett. I'm completely in love with them. Gaiman's fiction tends to be darker, but every bit as good as Pratchett's. The Discworld series (Pratchett) has become a part-time obsession for me, and there are enough books in it (30+) to keep you involved for a long without ever getting bored. There are several different series' that take place within the Discworld, so you don't have to feel like you need to get and read all 30 odd books in order. There's a Witches series, City Watch, Rincewind, and lots of stand-alones, as well as really good Children's books like The Wee Free Men and A Hat Full of Sky. Honestly, there's a little something for everyone.
Jam it back in, in the dark.