A personal favorite, the WORLD OF GREYHAWK box set [Gary Gygax, 1983] for AD&D is a feast for the eyes. The draw of the set is, of course, the gorgeous two-piece map of the eastern extents of the continent of Oerik. The maps are truly massive: The two sourcebooks in the set [Guide to the World of Greyhawk (80 pages) & Glossography (48 pages)] I’ve placed on the maps put their dimensions in perspective.

7th/8th printing comparison

WB RPG reference page

“World of Greyhawk” search at the sales site