I'm partial to playing Town of Salem in-browser. It's a web-based take on the game of Mafia and/or Werewolf (depending on the game-mode you choose).
If you've never played something like this before, this is a description straight from their webpage where you can also find the game (http://www.blankmediagames.com):
Town of Salem is a browser-based game that challenges players on their ability to convincingly lie as well as detect when other players are lying. The game ranges from 7 to 15 players. These players are randomly divided into alignments - Town, Mafia, Serial Killers, Arsonists and Neutrals. If you are a Town member (the good guys) you must track down the Mafia and other villains before they kill you. The catch? You don't know who is a Town member and who is a villain. If you are an evil role, such as a Serial Killer, you secretly murder town members in the veil of night and try to avoid getting caught.
Warning: In a game based on lying and deception, people can get rather salty.
A similar site is https://epicmafia.com/. It's more text-based, but has a greater amount of roles and customization to be played around with.