Fantagraphics. This collection includes all the comic strips from 1985 and 1986 and an introduction from comedian and actor Patton Oswalt.
The latest two-volume box set, The Complete Peanuts 1983-1986 Gift Box Set, which includes both Volume 17 (published earlier in 2012) and the just-released Volume 18 together in a special slipcase, is shipping as well.
Both the individual book and the box set are also available now from your local comic book store, or can be ordered from Amazon or other book stores.
For a 16-page preview, photos of the box set slipcase, and more information, visit the Fantagraphics website's pages for The Complete Peanuts 1985-1986 and the The Complete Peanuts 1983-1986 Gift Box Set.