Lego collectors from around the world are especially fond of collecting Lego buildings, some are original Lego sets and some are amazing MOCs they created on their own.
I personally really like the theme of the house building, especially the modular ones that come together in one big city.
I invite you to view some particularly impressive cities that I have found across the web

And of course you welcome to see the models I built:

Modular Building

 

Modular City

 

Desert Village Moc

 

Ruined City MOC

 

Las Vegas

 

Village