OpenTTD - An open-source clone of the classic game ...
Block'hood - A neighborhood-building simulator
Simutrans - Simutrans is an open-source transport simulator.
Streetmix - DIY urban planning
Transport Tycoon Deluxe - Transport Tycoon Deluxe is a Business Simulation developed by Chris Sawyer and published by MicroProse.
Cities: Skylines - Cities: Skylines is a Construction and Management, City Building, and Single-player Simulation developed by Colossal Order and published by Paradox Interactive.