Thanks for the list of games, Woody. I've never heard if Werewolf- or Mafia! I've never used Scrabble with a class precisely for the reason you mentioned, and I would love to hear if anyone has found a way to adapt it for learners.
I've used Pictionary before, the game where students rapid draw what a card tells them to draw and others guess as they draw. It's quite good for vocab as students are spitting out words and yelling at each other for a translation so they can get words out.
I'm also interested in trying out those role playing murder mystery games that occur at some parties in the US. The "host" assigns everyone a role. Each goes into character and tries to find out which among them is the killer. It's all oral skills and lots of fun. This site has a sampling of games to sell, in case someone doesn't know what I'm referring to.
This site has some short role play activities for ESL:
I've used Alibi in class with great success.