This was a great game when it came out in 2002 which complemented GTA 3 just nicely in terms of realism and an open environment.
The plot is set during the 1930's in a city that loosely resembles Chicago and New York with heavy influences from great mob movies such as the Godfather, Once Upon a Time in America and Goodfellas.
The player basically starts off as a taxi driver who unexpectedly picks up a member of the "family" and he quickly rises from being a wheel man to the Don's right hand man.
What made this game better then GTA 3 for me was the fact the police were actually competent and the player couldn't speed or drive like an idiot without being pursed by the police. You couldn't even walk in public with a weapon out because the cops would come and try to arrest or fine you.
If you guys haven't played it and love open sandbox time of games then I would totally check this game out, awesome story with twists and turns and a great soundtrack to set the mood of 1930's organize crime, totally worth the 10 bucks on ebay.