I've been sitting around watching movies for the past few days and thinking of places that don't really exist in FS, and I have a few ideas.  Unfortunately I am innept when it comes to designing airports or landscapes, so this would have to be someone else's project, but if you feel up to it, more power to you!

Cloud City (aka Bespin) from Star Wars.  This could be done in the same way the Alien City Destroyers were made for FS2002.

Jurrasic Park scenery.  Things like the raptor cages and a few miscellaneous dinosaurs around the island.

Arakeen City, from the Dune Chronicles.  Could be placed in the Sahara and even have some worms moving around about it.

And last but not least, some sort of Haley's Comet in the sky, when it is supposed to be there.

Anyone up for the challenge?