h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I used to derive much pleasure from this.

Tear up as many strips of paper as there are people present. On each piece of paper write a character for the player to be. Fold the strips, put them in a bowl get the players to pick them randomly. They musn't tell each other who they are. Describe a scenario and set them off.

Trivially the players get points for how well the enact the character as judged by you and this is how the game played until I discovered a far better twist.

Create subgroups of grossly compatible or incompatible characters say a psychologist and a psychopath, a guru and an ignoramus an arachnophobe and an entomologist.

For the ultimate spin make 5 of the six people something like islamic fundamentalists and the sixth Salman Rushdie and put them in a lift.