Dark_art_: Well, I'm going completelly of the charts now but older Bullfrog games do some "city" building with a lot of defense as well. Dungeon keeper, Populous 3 an Black and White (if you can manage to get a copy) are a very entertaining and fun way to build cities. Except when you get a vulacano in the center of yours!
When it comes to city building itself Black and White 2 stands out because trying to play in a more peaceful way by just building a big city feels so much more rewarding than the "regular" gameplay. Even just the city simulation itself is very rewarding just to watch since everything around your city feels so lively. Its kinda like The Settlers 2 but you're a god instead. Its still one of the most technical (talking about the tech behind the game here) city building games around where every moving part in your city feels like you had a say in it. Its a really rewarding approach towards the town and city building genre. Compare that with a game like Anno 1404, which rewarded optimization of your city more than esthetics (optimization and esthetics are very much alike, whats impotant is how the gameplay is structured to reward players making their city pretty rather than using 100% of your landmass properly) and on how the gameplay reflects this, which ultimately makes your town feel a bit more like a static grid and less like a naturally formed city. Anno 1404 is not the perfect citybuilder but its still very atmospheric and has great gameplay for a game like that.
Too bad Black and White 3 never came out, imagine them keeping the open gameplay of you being a god while optimizing the ideas of good and evil gameplay styles. Its seriously a idea worth pursuing again.
I also think that Populous 3 was amazing and very fun as well but thats mostly just because of the "cool-factor" of the hero unit using god-like magic. These type of games absolutely need a revival.