I posted this in the steam-punk wishlist, but think it fits better here (hope I'm not stretching any double posting rules too far)

Some early steel age interiors would be great:
Iron/steel paneling and doors, rusty pipes and ducting, iron bound vats, rows of heavy levers, large cogs, half cogs the reach up through the floor, and rivets, lots of rivets.

This allows interiors for ships, tramp steamers, warships, factories, subs, heavy gun emplacements - you name it, if it's pre-1960s heavy industrial these interiors would be great (and lets face it, this stuff was so solidly built there's a lot of it still about).
Can just see the zombies crawling out from the heart of the old abandoned factory. This stuff can even be integrated into fantasy dungeons as was done with dwarven ruins in the Morrowind PC game.