I've played so much of these games, and here's my opinion on them:
- City Life 2008: Kinda easy in my opinion, but I absolutely love the free-angle roads and the culture system is quite interesting. It's a good spin on the city building genre. Oh, and the street view... MAXIS HAS BEEN PROMISING THAT s**t AND THEY DIDN'T PUT IT UNTIL SIMCITY SOCIETIES AND THEY SAY IT'S THE CRAPPIEST GAME OF THE SERIES.
Simcity 4: The most complete and complex simulator in my opinion. Building a city from the ground-up is a great challenge and it has oh, so very very much hidden depths. ********, even architecture students use it for their urban planning classes!
Simcity 2000: Yes, SC4 is complex and complete, but Simcity 2000 is the hard one IMO. Budgets are way slower, and you'd better have hydro plants while your city is still growing or your power plants will a splode all the time!
Lincity: A very interesting take on the city building genre. Instead of building residential and commercial zones, you build structures that provide different resources. Cities end up being ludicrously unrealistic, but it's a quite good system IMO. Could use more skins for the buildings though. Available for Linux under the GNU GPL license, which means it's GNU freeware ^^
SimTower: Another interesting take on this genre. Instead of building a city, you build a building. Quite good in my opinion. I've already built a skyscraper that has reached the TOWER rating ^^
So, which is your favorite city building game?