We all have a competitive nature and the Wii seems to bring it out. Whether it was tennis, bowling, or boxing watching family vs. family was quite entertaining.
But not as entertaining as watching the flailing of arms and bodies playing the game! My father-in-law was addicted to bowling. My brother-in-law took particular pleasure knocking out his wife in boxing, and my sister-in-law swore like a sailor playing just about every game (I didn't realize how competitive she could be!). Oh yeah, there was plenty of bruises too as spatial boundaries were violated by swinging arms and hands!