I found The Twin, by Gerbrand Bakker, sitting on a coffee table at a writers' colony in 2009. It carried praise from J.M. Coetzee for its "restrained tenderness and laconic humor," which seemed ample justification for using it to avoid my own writing.
I finished it, weeping, a day later, and have been puzzling over its powerful hold on me ever since. I've recommended it again and again, and while I can't say it's entirely undiscovered — it won the 2010 IMPAC Dublin Award — no one I know ever seems to have heard of it.