The Family Stone (2005)

I am not sure how I missed this movie when it came out, because it is packed with people that I like, and unlike many of my close family members, I do like a dysfunctional family oriented Christmas movie.  That was the short story of my whole childhood.  Also, for a moment my whole family was thinking that we had seen this movie already because we had  just watched Love the Copper's, which also stars Diane Keaton as the mother in yet another family which anyone with their head screwed on straight would avoid coming home to.
But come home they do.  In this case all five kids.  The golden boy of the family brings home a woman who is wholly unsuited to him and he brings out the worst in her.  Which becomes abundantly apparent under the scrutiny of his entire family.  But not to worry, they just picked the wrong sibling.  There are scenes that will remind you of Much Ado About Nothing, and once you get over being annoyed in the beginning, it is a good movie.