Pretty much the best citybuilder and one of my most played games of all time. I own a physical copy of it, and I recently picked up this Steam copy... definitely one of my favorite games ever.
You need to mod the game in order to make it playable, and the game tends to crash, lock up, and run slowly. There's no autosave and you'll probably lose a lot of hours of gameplay. Loading a custom region is cumbersome, installing mods is archaic, and the whole thing is just clunky. Using some mods will require literal hours of patience... ask me about custom highways or building a mass transit network. Piece by piece, slowly, surely, but satisfyingly.
Beneath all the clunk is a diamond, the absolute best city builder of all time. Every game that comes out can't seem to match a well-modded Simcity 4. You can install a massive amount of options for mass transit and building variety. It's intoxicating, if you're into it.
If you just want to build a pretty city, you're going to need to work slowly and learn how to do it. This game honestly isn't friendly or accessible for new people... But if you work at it, and you enjoy the genre, you're going to love it.