IF you get SC4, get the Deluxe version (It's little more than SC4 + Rush Hour, all in one package). The Rush Hour pack adds loads of useful tools, and some other road types.
Also consider getting the Prima guide. It's a few hundred pages of useful information, such as building stats, and how the simulation engine works. The game's got all kinds of fun little tricks, too - for example....possible spoiler, if you want to call it that. Those are farther down.
Yes, SC2K was probably the best. My biggest city was nothing but Launch Arcologies and police stations - one station per arcology.
SC4 - my biggest complaint about it is that it is crash prone. Scrolling around a city, try to check a building's stats, and the game crashes back to the desktop.
Worse yet, it can freeze when it's saving a city, and that can corrupt the file. So, when you load the city, there will be a part of it that wasn't saved properly. When you even try to
look at that section of the city, the game crashes back to the desktop.
I don't know if it's just my system that it doesn't like, or why it does that. I don't like to save constantly because, especially on the big 256x256 maps, saving the whole city can take at least 30 seconds.
Electronic Arts owns Maxis, so that's probably why the game line started to suck.
Oh, and with the Deluxe Version/Rush Hour pack, there's a Grand Railroad Station. It's supposed to unlock when your R+C population reaches 172,000. It doesn't. It's a known bug that they just never fixed, because, I don't know, they're EA maybe? Two ways to unlock it: use one of the driving missions which unlocks it, or just use the cheat to enable all of the reward structures.
Tip: start small. Don't plop down a coal power plant and high density structures right away.
Start out with a wind turbine, a few low density residential and commercial zones, and agriculture. You also don't need water towers or pumps until you start zoning medium and high density, but you can probably get a few thousand people into your town before you'll start wanting them.
Do that, and it's actually easy to turn a profit quickly. Not a big one, as your budget will be fairly low, but it should be positive. Don't worry about police, schools, or hospitals until you've built up a good tax base.
And right from the start, enable the Smoke Alarm ordinance. It only costs 20/month, but it reduces the chance of having to start a fire department early in the city's life.
Fun tactic to use, but it kind of takes advantage of some quirks in the simulator:
If you build a city/suburb with NO residential buildings, it makes a lot of things easier. There are no citizens to get sick, or complain about pollution, or cause crime, or want education and health services. Result: it can be a filthy city that provides loads of industrial jobs, and since there's no one to complain about environmental issues, you can set up coal power plants (and use neighbor deals to sell the power to adjacent cities), for cheap electricity. To get rid of garbage, use the trash-burning power plant, and set its funding to 0. It'll still burn loads of trash, but won't cost anything.
Landfills - don't bother. If you want to get rid of them, it takes many many decades for the trash to decay away.
Also, if it's a really junky city, with nothing but dirty/manufacturing industrial buildings, with no residences, and coal power plants, try to get the reward structures like the casino, missile launch site, army base, federal prison, and toxic waste dump. The city's already home to low-land-value property, and I-D especially doesn't give a damn about property value. These reward structures will pay your city money just for being there.