Woah, woah... WOah! I don't know if this is new, or what, but Sim City Classic is totally freeware :
http://simcity.ea.com/play/simcity_classic.phpEDIT: Oh wait, should have tested this better first, it's like online, and it's not working in Firefox, it says it wants... NETSCAPE NAVIGATOR? does anyone use that I thought the monopoly Microsoft had killed it.
Not only that but uh, you have to register on their site, bad call on my part.