GANGSTERS: ORGANISED CRIME
Eidos Interactive
You need to explore a few game folders for this one, but it's worth it. Go to Run in the Start Menu and type 'regedit'. Now navigate through the following directories: 
\hkey_local_machine\Software\Hothouse\Gangsters\. At 'Default Money', change 2710 to 207101FF for unlimited cash. At 'Default Hoods', change A to FF to start with loads of hoods.