Just spend the ~$150 or so to buy a steam cleaner. You can probably even charge a one time "membership" to your drunk friends for the honor of hanging out at Maverick's Bar and Pong House in order to finance it. All the plastic/tarp/area rug suggestions ignore the fact that stuff like that doesn't necessarily stay put when you get a party going on. Besides the fact that it looks cheap - like covering your furniture in plastic before you let your guests sit on it.
