The NDEX mansions are pretty good, but they do not fit in so well with typical american style architecture. It would be nice to see some american northeast style mcmansions with attached garages, etc... also it would be nice to see some more in scale to the rest of the game :)
Here's an example from my town (in CT) that i would like to see in the game:
more examples:
those are some monster houses lol.... i hope some will bat them
it would be great if someone did these, there are also that arent exactly "MCMANSION" but would be nice ingame take a look at this subdivisioin in Delaware http://villageofbayberry.com/ :D