The first game in my opinion is THE best game based on organized crime, the sequel looks very promising! So far no news about online multiplayer in Mafia 2, I think there won't be one...
I would vehemently disagree with you there. The GTA series is really the best at it, they're much more versatile and I actually believe their narratives.
On organized crime itself? Yes. But on the mafia? No. IMO
