There's the Caesar & Pharaoh series which does something along those lines, albeit with ancient cities.

Don't forget Zeus, which is the best in the series in my humble opinion!

Well there was Streets of Sim City[0] where you could take any of your Sim City 2000 cities, and turn it into a vehicular racing and combat playground. Way fun at the time!

0.http://en.wikipedia.org/wiki/Streets_of_SimCity

SimCopter was pretty fun too, but game was more about Commercial missions and civil protection

http://en.wikipedia.org/wiki/SimCopter

I loved the in-game radio and the enormous number of goofy/awful commercials. It was a huge amount of fun to build a city in SC2K or SCURK, fly through it running missions, and then burn it to the ground with an Apache "fighting crime" (aka clearing traffic jams the easy way).

The thing I remember most about that game is dropping wounded passengers because my heli couldn't keep the load up in a storm :-)

Loved that game, it was for me like a light hearted version of GTA without all the dark overtones. That's really what would make SimCity a game I would have kept upgrading to; that and support for Linux. Their main page says PC/Mac. So PC means Personal Computer, wonder if my PC running Ubuntu counts? I'm guessing no. I'd have kept upgrading the BattleField games too but EA seems to not be interested in this.

Have you tried Stronghold? It's like SimCity in a medieval setting, though with much finer-grained control on what you build where (placing specific buildings and laying out walls, rather than allocating general "zones"), and in most scenarios you need to build troops to defend against periodic attacks from enemy armies.

ETA GOG link: http://www.gog.com/game/stronghold

Take a look at Factorio. It's not perfectly what you're looking for, but the state of mind that it puts me in is right in between starcraft and sim city.

Anno 2070 might fit the bill.