I'll throw out several ideas.
The Oxford Companion to Chess, 2nd ed. - Fairly good sized book, decent colors, and, hey, it has "Oxford" in the name!
Chess: 5334 Problems, Combinations, and Games (hardcover ed), by Laszlo Polgar - It's huge! Also, cool photo of chess pieces on the front of the jacket. What's more, the spine of the jacket is impressive enough, so you don't even have to take it off the shelf. Even the publisher's logo is cool (Black Dog & Leventhal, with the outline of a dog.)
The King, by Donner - OK, maybe not too impressive visually, but LOTS of snob appeal among the hoity-toity crowd.
And maybe my fav (at least with only a few minutes of thought):
Shady Side, by John Hilbert - Decent sized book, cool blue dust jacket, cool fonts used for the title. And what better title than "Shady Side: The Life and Crimes of Norman Tweed Whitaker, Chess Master", complete with a front and side view mug shot on the front of the jacket.