I've got Sim City 4. It's really neat. The strategy is MUCH different from the other games though. You have to start off with light residential and commercial, and either medium industry or farms. You can waste your money on the dense zones, but they WON'T develop until you have a large population. It's easy to rezone though, as it doesn't destroy the buildings already there.
New kinds of roads are kinda cool too. Slightly different power plants, better control over taxation (you can tax lower, middle, and wealthy classes in each of the RCI).
What's really neat is you have control over a huge region. The region is broken into many maps of varying sizes which you can start your own city on. This makes for some interesting options. I have one city which has all the landfills, industry, coal plants, water production etc, and it's basically a pollution hole. It has no residential or commercial at all. It makes most of it's money by selling commodities to the neighbouring cities. This allows my other cities to not have to worry about paying and maintaining a huge coal plant or a water system (pay as you go type thing), so it's much more efficient.
Some day I'll be rich and famous for inventing a device that allows you to stab people in the face over the internet.