Rome wasn't built in a day, either. Entirely depends on what you want it for. One image, a backdrop to a vicki-lounging-in-a-penthouse-apartment pic, I'd use a photograph. A quick fly-over or a superhero poised high over a fog-enshrouded metropolis, I'd head towards our friend Moius and his "Dystopia." For a close-up street scene I'd think strongly of StoneMason and his marvelous back-alley dioramas. So where are you heading with this? Realistic or cartoony? Long shots or close-ups? Historical, present, or futuristic? A one-of, an animation, a model to provide to the community? Please tell.