This one actually saddens me. After the passing of Ray Bradbury, who was generally my favorite author, now comes Gore Vidal. And in the same week as the passing of Alexander Cockburn, no less.
Despite being someone with whom I occasionally disagreed - particularly in his later life - I found Gore Vidal to be incredible in his sly wit and his ability to write provocatively in a way that retained a great deal of wit and a shocking amount of empathy (within his writing, anyways, which wasn't always something he translated to speech) for his enemies.
Julian, the story of the last Hellenic Roman Emperor, remains one of my favorite books - and still the one I would recommend as a read. His Empire series is widely (and probably most) appreciated, so there's no need to mention them here, but he also did some important work for the shifting discourse on sexuality within modern culture. From Myra Breckenridge to claiming that he'd written a homosexual subplot into Ben-Hur (which is awesome precisely because it's so easy to believe), he was a fascinating character. Even Live From Golgotha, ridiculous as it is, becomes a riot when you read it considering what people truly believe about their saviour and imagine turned into a media spectacle.