This goes with the forementioned and the ArenaWorks, but how about more Roman and/or Greek buidlings? They have a distinct archtecture to them, and I can think of about 50 different items you could have in the set (including Aqueducts, columns, marble floors, small pedestals, vases, etc).

Although, no one but I may be interested in this idea.

If Denny builds it, we will come... wallets in hand!

You know, I thought about that, too.

Roman style architecture, especially that used on government and bank buildings, could be used in hero RPG/mini games, too. Since a lot of comic book worlds portray buildings with Roman styles all the time.