I'd build an exclusive country club-like atmosphere.
You'd have to pay membership dues of $10,000 a year or more just to get in (assuming you are good enough to get past the membership board, after being on the waiting list for a couple of years). And naturally only adults would be allowed (probably no ugly adults, either).
It would have fancy leather chairs and couches. There would be crystal glassware containing fine scotch and brandy, and a fully-stocked walk-in humidor with fine cigars (included smuggled-in Cubans sold under the table).
The entire interior would be made of fine Oak and Black Walnut. The floors would be marble tile with 24K gold inlays combined with hand-woven Oriental rugs.
There would be a fancy library room with built-in bookshelves filled with every RPG ever produced.
There would be "drink girls" in skimpy outfits that would refill your brandy while you were playing, as well as offer you snacks like canapes, sushi, and caviar.
The bathrooms would have two full-time attendants. And instead of toilet paper, guests would use bidets and rolls of silk.
And in the game rooms, you'd hear such banter as, "I say, good chap - I do believe my elf gets an attack of opportunity against that orc." and "I do believe my die has gained some kind of gypsy curse. It rolls lower scores than my gardener's IQ."
What?