Peter Watson's German Genius, a thousand pages of German intellectual history, though the writer is much more fascinated by early twentieth-century philosophers and much less by early-twentieth-century scientists and engineers than I would have been.
Daniel Yergin's The Prize, a really detailed telling of the first 130 years of the oil industry; household names - Getty, Rockefeller, Gulbenkian - and an understanding that I didn't previously have of how completely oil-drenched all Western interactions with the Middle East have been since well before World War Two, and of how recent the oil wealth of places like Libya is.
Hans Fallada's fantastic Alone in Berlin, a lesson in the paranoia and the complete institutional sickness of the Third Reich; on a much fluffier note, Paul Torday's Salmon-fishing in the Yemen, which is a Blairite political satire cheering to read in that it reminds you of a time when the worst feature of Blair was his PR-run and cheer-driven politics.
I can't recommend Thomas Levenson's Newton and the counterfeiter, it's a dry telling of some bits of history which were much improved when Neal Stephenson used them as the backdrop for his Baroque Trilogy.
As for SF, I've already enthused about Kirill Eskov's The Last Ringbearer a few articles ago. John Scalzi's The God Engines didn't do much for me (in particular, it didn't do much for me that Warhammer 40,000 hadn't done when I was fourteen). Paolo Bacigalupi's The Windup Girl, which reminded me of Neuromancer as much as anything else - a tale of corruption and societal collapse set in a drowning Bangkok. Adrian Tchaikovsky's The Sea Watch which at least answered the question of what was left to write about in his thoroughly-explored world, and had some marvellous underwater set-pieces. Jo Walton's Among Others - a tale of self-discovery in the hostile world of a 70s girl's boarding school, with ambiguous magic, fairies and Wales.
And I re-read Patrick Rothfuss's The Name of the Wind, amazed at how much of it I'd forgotten in the four years since I read it last - it was definitely a book that I sat and read until 3am the first time, and it turns out that in reading at 3am I managed not to embed into my brain the entire two-hundred-page sequence with the forest of opium trees and the maddened dragon-lizard.