I found the 50k houses a little uninteresting for me so I settled for one in the bogs - though I'm not really attracted to that sort of dark environment.
I've always liked the art of William Heath Robinson. http://www.google.ca/search?rlz=1C1AVSA_enCA433CA433&gcx=c&q=william+heath+robinson&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&hl=en&tab=wi&biw=1342&bih=625 Love to collect those posters.
I also like some of the steampunk envirnoments in secondlife. Exploring industustrial wastelands is also fun - both in real life and in games.
some of these "places" are cool:
http://londonist.com/2011/09/imagined-cities-london-design-festival.php
I would love to have a house in the world of Amy Casey
http://www.thisiscolossal.com/2011/07/amy-casey/
Since we live inside the Giants, why not visualize our neighborhoods as part of their dna or their internal organs?
What else? people have mentioned water environments. Maybe underwater caves or something?