The Three-Body Problem

The fun ideas in this book keep it together, just barely. The characterizations are pretty weak, the plot cobbled together, and deux ex machinas abound. But it's still totally fun, and has some interesting ideas about what first contact could turn out to entail (spoiler alert: factionalized earthlings and aliens, and war). I'll read the sequel just to explore some more of the ideas, for pretty much the same reasons I've enjoyed Philip K. Dick books–crazy ideas, clunky writing.