Zoning is a really interesting one. It's a damn shame there isn't more mixed zoning.. Would have been rad to grow up in the burbs, but still have some shops and such in the neighborhood, rather than needing a car to drive across town to get anything done. Maybe I wouldn't be so allergic to suburbs if there was something actually there.

Zoning laws could probably be blamed for our total lack of cultural cohesion and Third Places. (Speaking from a US perspective)