Its interesting that outside of New Reno, there is really no mention of organized crime. I'd be interested to know, what happened to the Mafia, the Irish Mafia, and the Jewish Mafia(all who were fairly large players in 50's America). Hmmm...makes me wonder....What happened to Jimmy Hoffa?

Gizmo and Decker from Fallout 1?

Various Raider gangs? (Or is that more of an example of disorganized crime?)

Several random encounters in FO2 had you running up against Mobsters and Yakuza in the Wasteland.

I think organized crime needs a fully functional society for it to operate, of which there are very few in the Wasteland.