Adapted from "Busca tu cancion" in 101 juegos musicales. See also I second that (e)motion.
The joker writes down three to 10 emotions on index cards, two cards per emotion. (One set of three if you have an odd number of participants.) There should be as many cards as participants.
Shuffle the cards, keeping them face down, and have people pick a card, keeping it hidden from others.
When the joker says, "go!" the participants start wandering around the room expressing their emotion (facial festures, body language, improvised language, etc) and seeking the other person with the same emotion. When they find their partner, the two sit down.
The joker asks each pair to express their emotion, and asks the group to identify it (of course, multiple words can be used to describe a given expression of emotion -- this can be a useful activity in itself, building a richer list of emotions).
Variation: use the chart of facial expressions from Alforja Volume 1 instead of words, then have people name the emotions after they find their partner.
You could end by having each pair improvise a one minute scene that illustrates the emotion.