If you haven't already, Douglas Adams and Terry Pratchett are both hilarious mind-candy type authors. Fairly quick reads too, for the most part.
I really enjoyed Jay Lake's two recent novels,
Mainspring and
Escapement. Both fantasy/steampunk (though this world runs on clocks, not steam) type novels, very vivid and rich.
R. Scott Bakker's Prince of Nothing series is very good, extremely dark high fantasy(be prepared for blood, sex, and navel gazing). An incredibly well-crafted world. Always a sense that there's more to the backstory and mythology of the world, and oftentimes you get to find out about it later. The series begins with
The Darkness that Comes Before.
A couple of classic sci-fi authors whose work I really enjoy: Philip K. Dick (
A Scanner Darkly,
Do Androids Dream of Electric Sheep?, and countless short stories, among others--very dystopian early sci-fi, often questions the nature of reality and what is real), and Frank Herbert (author of the
Dune series, among others--one of the most well-crafted universes in the history of SFF, in my opinion; I think everyone should read at least
Dune).
I'm a bit of an SFF geek. Can ya tell?

Let's see, who else have I enjoyed reading recently?
I recently read
The Queue, by Vladimir Sorokin (translated from the original Russian). A very good story, about Soviet era Russia--a time when people waited in huge lines for even days on end to obtain goods. not exactly a novel--it's a series of unattributed lines of dialog. Kind of meaningless noise to begin with, but clear characters begin to form almost immediately.
For a good mindfuck novel, try Robert Shea and Robert Anton Wilson's
Illuminatus! trilogy (usually sold as one book). Lots of cognitive dissonance, slips in and out of various perspectives with no warning, and just generally a head trip.
That's all I've got right now. Hope you find something in there you like.