SimCity was a disaster. Cities XXL was a scam. Cities: Skylines must be thinking, hey, hopefully third time's a charm.
Out next week, it's a city-building game that's looking to get things right by, well, not doing anything wrong. It has big city plots with plenty of customisation and modding options, and looks pretty nice to boot.
I've noticed a few quirks in my time with the game so far, but hopefully they're things that can either be fixed pretty soon or modded out by fans.