We've reached a point where video games can recreate real cities. I first noticed this with Spiderman 2; I played it for 20 minutes and suddenly thought "wait a minute this is New York!". I recognized it from the virtual street layout.
My favourite thing in Grand Theft Auto: San Andreas is the virtual place. The street layouts are heavily abbreviated, but it still feels like Los Angeles and San Francisco (haven't been to Las Vegas yet). And the landmarks are well duplicated, to the point where I learned what the Watts Towers looked like first in the game and only later in real life.
GTA: SA goes beyond just landmarks to create the virtual place. Different neighbourhoods have different people with different dialogue: vapid blondes on Rodeo Drive, tough gangstas in East Los Santos, swimsuits on the beach. Different areas have different cars: lowriders in Hispanic neighbourhoods, big ol' trucks in rural areas tuned to country music. Even the street furniture and generic house templates change: ranch homes and box apartments in Los Santos, Dolger Homes in San Fiero.
It all comes together to make the virtual environment feel real. So much so that when I could finally go to San Fiero, the first thing I did was drive around until I found the Castro ("Queens"). And I knew I was there because there were rainbow flags, gay clone men spouting campy dialogue, cute little sports cars, and stores named "The Barber's Pole" and "Gaze Glasses". I was home.