Play American Bandstand
Have a couple of designated judges. As the music plays, the judges move through the dance crowd, watching and evaluating. If the judge taps a couple, they're out of the contest and must move off to the side. Eventually, the dance floor has been cleared to just a few couples. At this point, let the audience become the judges--their vote taken by the volume of applause as the judges indicate one couple at a time.
Host a Dance Competition
Model a dance competition after "Dancing with the Stars." For this, you'll need to either hire professional dancers (consider hiring dance instructors from a dance school for the evening) or have someone at the party who knows numerous dances. Couple who wish to compete line up. The professional dancers demonstrate a particular dance, such as the cha-cha-cha or rumba. The couples then take turns replicating this dance for the audience and judges. Assigned judges can raise numerical score cards, or even just "yes" and "no" cards, to determine if that couple advances to the next dance. Or use audience reaction as the vote. After each couple performs the first demonstrated dance, those who were voted to continue on watch the second dance and imitate. This continues until there is only one couple remaining. If using numerical scores, each couple can compete in all dances, and the winner is the one with the highest total score.
Follow the Leader
One person on a stage is the dance leader. Everyone must copy the leader's dance moves. When the leader freezes, anyone who doesn't freeze is out of the game. Also, anyone unable to follow the moves or who loses her balance and falls over is also out. Play continues to the last person standing.
Close Quarters Dancing
In this game, each couple is given a piece of newspaper. Because of the wear and tear of paper, couples may wish to dance barefooted or in socks. Each couple must dance while keeping their feet on the open piece of newspaper. If one person from a couple steps off the paper, that couple is out of the game. When the music stops, the newspaper is folded in half, the music resumes and the game resumes with the couple now dancing closer and on a smaller space. This pattern repeats until no one can stay on their paper any longer.