I... used to love Sim City 2000. ._. I can't even begin to imagine how many hours I probably spent playing it as a kid. I remember once I actually learnt proper zoning laws and stuff in school, I actually got better at it; that was one of the times my eyes were opened to the fact that school was useful. XD
My favourite part was still opening up a premade city and unleashing every possible disaster on it, though. 8D
...damn, now I really want to play it.