Assassin's Creed II, and the other Assassin's Creed games. The cities look absolutely perfect, especially if you're playing on a PS3 with a television that can use those HDMI cables. Cities such as Venice, Florence, Tuscany, and some others. Those are the ones I remember. They are in great detail.
Also Grand Theft Auto IV. They did a great job on that game.
Assassin's Creed 2 and Brotherhood, the cities are almost real, because I've been to Italy. I can't say about Assassin's Creed 1 because I never been in the Damascus city area.
GTA IV is realistic too, but when you are put into the middle of New York, you are lost...cool thing the game has a map.
Cities XL, there are some pre-made cities such as Paris, Miami and Berlin, which look like almost the same like they do in real life.
assassins creed series made old cities look very real of cource assassins creed 2 made florance like real and saboteur that is WW2 in paris made paris city amazing i reached top of eiffel tower amazing game and city creating paris was like old days it felled real