RollerCoaster Tycoon 2
PC / Chris Sawyer Productions / 2002
This is easily one of the best sim games I've played. RollerCoaster Tycoon 2 is just a hell of a lot of fun. It has a huge amount of things you can do and gives you a lot of freedom to create whatever you want, while still having some sort of goal-based campaign to give you reasons to keep going. I don't really have a lot to say about it - it's really just a very fun game about making your own theme parks. Yeah, that's it.