I've really been into S.M. Stirling's latest series, Dies the Fire. I won't vouch for it's worth as literature, but I will say that it presents a really fun idea that is fairly well executed. The basic premise is that some kind of mystical/super-science event wiped out the capacity for "high-energy" technology all across the world. By "high-energy", I mean gunpowder, internal combustion engines, steam power, electricity, nukes, etc. The concept is well-thought out, especially concerning the effects on civilization as the world's critical infrastructure ceases to work. It's not a world I'd like to live in (obviously), but it is a fun world to fantasize about, which means it would make a great game setting.