I really don't think there's any place on earth that's not planned, to be quite honest. I think we're using the wrong word here.
If you look at a city like Paris for example, Haussmann's plan, in my opinion at least, has created an absolutely stunning and unique city. But within it, there's been a lot of room for organic development.
But if you look at a city like Detroit, you get the developer-dictated sprawl you mentioned. But that, too, is planned. If you create building permits for block after block after block of single-family detached home, you get detroit's urban sprawl where you'll figuratively die of hunger in the unfortunate case your car is out of fuel and you need to walk to the nearest mall haha.
Anyway, I think in general European cities have gotten it right quite often. Lots of open spaces, green spaces, make cities walkable, good public transportation, mix housing with light commercial areas, keep heavy industry outside of the city, mix housing catering to various socioeconomic classes, create a good amount of density so you don't get sprawl, but so you don't get overcrowding either, and focus (public) transport on connecting residential and office/commercial areas. You usually get a great quality of life, little polution, social cohesion, affordability, little social tension, and create an impression that it's unplanned and organic (i.e. don't use graph paper to model a city)
I agree, "planned" may not have been the right word for me to use, since most cities have had at least some degree of planning in their development.
I reached for that word because (in the modern-day US, anyway), a "planned community" is a very specific thing: a giant, car-centric tract of residential housing, with the developers making a nod towards the needs of real communities for things like grocery and other retail shops by plunking a shopping or strip mall in the middle. It's the Levittown (http://en.wikipedia.org/wiki/Levittown,_New_York) model, but with McMansions instead of the small Cape Cods and ranch houses (http://tigger.uic.edu/~pbhales/Levittown/building.html) of the original post-WWII building era.
The sentiment I was trying to express was that the homogeneity of building everything at once made Songdo sound more like that than it did a city like, say, New York, which (while there have been master plans guiding development there too) can still feel diverse and lived-in.
If you look at a city like Paris for example, Haussmann's plan, in my opinion at least, has created an absolutely stunning and unique city. But within it, there's been a lot of room for organic development.
But if you look at a city like Detroit, you get the developer-dictated sprawl you mentioned. But that, too, is planned. If you create building permits for block after block after block of single-family detached home, you get detroit's urban sprawl where you'll figuratively die of hunger in the unfortunate case your car is out of fuel and you need to walk to the nearest mall haha.
Anyway, I think in general European cities have gotten it right quite often. Lots of open spaces, green spaces, make cities walkable, good public transportation, mix housing with light commercial areas, keep heavy industry outside of the city, mix housing catering to various socioeconomic classes, create a good amount of density so you don't get sprawl, but so you don't get overcrowding either, and focus (public) transport on connecting residential and office/commercial areas. You usually get a great quality of life, little polution, social cohesion, affordability, little social tension, and create an impression that it's unplanned and organic (i.e. don't use graph paper to model a city)