I'm up to 120 blue houses and counting... not many compared to some but I have nice symmetrical streets in between :D and not many can say the same from the neighborhoods that I've seen!
I'm currently devoting all funds to purchasing land and building blue houses, I can fit about 4 houses per new lot and now make $18,000 every 8 hours.
Come see my neighborhood for yourself
add: duckinabearsuit
Have you put streets in between all your houses or come up with a unique house-farming tract? Let's see a screenshot!