Dune: House Corrino - Brian Herbert and Kevin Anderson
One of a series of prequels, or however they may be designated, which match, or possibly exceed at least the later originals, IMO.
There have been a few grand series I've encountered in the past that not only left me pining for more generally, but seemed to leave whole worlds of primary character realms unexamined except in teasing fashion.
These two have ably corrected that (I suppose) necessary neglect as it relates to the Dune series.
The latter additions are more readable as well as more of what I wanted than the second trilogy of the original series.