Fuckin Neal Stephenson.
Currently in the middle of his 3-part Baroque Cycle.
He rose to fame with Snow Crash and the whole cyberpunk genre, but these books are no-shit fantastic. He wrote them all longhand in 2 or 3 years, and it's a total of around 2500 pages. And the best part is that the stories are so damn engaging. The characters are huge, development-wise, he's not afraid to kill a few off, and he even manages to defeat the Trilogy Demon and provide some semblance of resolution at the end of each book. As for genre, it has a cyberpunk aura, but it's most obviously historical fiction-- takes place in the 16th-17th centuries, revolves around the politics in England at the time (the Restoration, etc.), and Sir Isaac Newton's strange journey through life and machinations regarding currency, as told from the points of view of 1) a cohort of Newton's, 2) a swashbuckling mercenary/pirate, Vagrant, and 3) a former Turkish slave who rises through the nobility of both France and england, even while they war.
It takes a little while to get started but it doesn't stop. I'm on the third book now and i just wish i had more time to read... If you're new to stephenson, i'd actually recommend his previous book Cryptonomicon. It's only one 900-ish page volume, and it's more modern, switching between WWII and modern times, with treasure hunting, digital economy building, Germany-foiling, cryptography, and of course a wonderful budding romance. I cannot recommend either of these nearly enough.