Hidden role games; I love 'em. But mostly for the social aspect at the gaming table; not inside my PC over the magical tubes that make the internet. The main draw is a randomly assigned team that has "perfect information" playing against the uneducated masses. In Town of Salem that means its the mafia out to get the town. It works surprisingly well considering the limitations of what is essentially a chat room with rules.
Games set up quickly with three players being assigned roles as mafia and being identified to each other mafia member. The rest of the players are divided amongst various town or neutral roles (including a serial killer who is out against everyone). At that point the premise is simple: mafia kill townies, townies figure out who the mafia is and lynch them. The fact the mafia know each other and the townies don't know anything other than their own role opens the doors for all kinds of social shennagins. Is that guy saying he is the jailor really the jailor or is he the godfather laying waste to townies at night? Throw in a handful of neutral roles such as the jester (who wants the town just to lynch him) to the aforementioned serial killer who is out to kill everyone and you have a very unique game of "who's who" and "who dun it?".
The game is available via Steam or their website.