Gangsters: Organized Crime
http://www.gog.com/game/gangsters_organized_crime I'm surprised this hasn't been mentioned yet. It's a rather complex gangster simulation with countless possibilities to make money, kill your opponents and rule the city. It's a mix of turn-based and real-time strategy. You plan your week and give orders to all of your henchmen, and then let the week play out.
Edit: Judas, if you're still reading this topic, you can remove the compatibility notice on the store page.
"ATI/AMD compatibility notice: Gangsters: Organized Crime requires graphic card drivers version 13.4 or older."
The game used to be incompatible with AMD cards up until half a year or so ago. But ever since updating my drivers a few months ago, the game works fine, even on the newest AMD drivers (Catalyst 14.4).
Edit2: The same goes for Rollercoaster Tycoon 1 & 2, by the way. Like Gangsters, both of those used to have DirectDraw issues on AMD cards, but not anymore.