War, magic and some more war...
Iain M. Banks - Use of Weapons - The third Culture novel, although it can be read as a standalone. Stunning book, with one of the most labyrinthine structures of anything I've ever read. Dark, questioning and it will stay with you.
Jim Butcher - The Dresden Files Series - The best urban fantasy series on the planet. Butcher doesn't just write great stories with great characters, but he creates a truly believable world in which those reside. I have yet to meet a single person who has read a Dresden Files book without getting hooked. The first book, Storm Front, is the weakest of the series, but it's still better than most books you'll read, and the ones following it just get better and better. Humour, drama, action, wit, plot and lots of magic. Literally and figuratively.
A pair of books to read in series:
Adam Zamoyski - 1812 - The story of Napoleon's catastrophic campaign against Russia. Brilliantly written and gripping. A story of pride and hubris coming back to bite.
Stalingrad - Antony Beevor - As far as I'm concerned, Antony Beevor can do no wrong when it comes to military history. This is a thunderous book, which brings the futility of Operation Barbarossa into clear light.