For me, it would be cranium. A great party game and it offers something different that me and my friends enjoy. .
http://www.amazon.com/exec/obidos/t.../104-5063521-5643942?v=glance&s=toys&n=507846
http://www.amazon.com/exec/obidos/t.../104-5063521-5643942?v=glance&s=toys&n=507846