My Greyhawk looks like this.

This is an illustration done for Hans Christian Anderson's fairy tales by Edmund Dulac. Around 190-something, I don't recall now. I can't think of anything recent that has this sort of detail and life in it's illustrations. Even with the early chromo-lithography printing this was scanned from, the longer you look at it, the more little details you pick up.

I love this Alchemist/wizard, the golden glow of whatever it is he's created in that bottle reflected in his eyes. The armillary, books, bottles, chests, lamps, and, dare I say it, accoutrement's of wizardry all about the room.

Here's a cropped closer view of the wizard himself.

This is the quality of art I would love to see in Dungeons & Dragons books. I would give your left arm to have a Dungeon Masters Guide illustrated by Edmund Dulac. What? I can't give my left arm, that's my shield bearing arm. Shut up and hold the torch higher, I can't see the bottom of the pit.