Right now, I'm working my way through all of Terry Pratchett's Discworld novels. Currently about half done with Lords and Ladies. That'll be fourteen books, and another twenty-five to go... I've already read most of them, but never all in one go. They're definitely worth rereading, though.
For people who aren't familiar with them, I'll put it this way: imagine Lord of the Rings written with the humor of Hitchhiker's guide to the Galaxy, but weirder, and oddly reflecting our world. The series was off to a kind of shaky start with the first couple of books (they were still good, mind you, but read more as a series of vaguely related short stories than a cohesive whole), but after that Pratchett really caught his stride, and hasn't let up yet.