I'm pleased that at least one person has suggested films from beyond the USA.
One very interesting film revolving around a wedding is The Wedding, directed
by Andrzej Wajda.  (I don't have a release date reference ready to hand, but I
think it was from the mid- to late 1970s.)  I saw it a number of years ago in
the context of a screening for international students, and there was some time
set aside after the film for discussion, which I was supposed to lead.  For-
tunately -- because I was somewhat confounded by the film -- there was a
Polish fellow in the group who was able to explain the film exhaustively.  The
first point he made, though, was that the film was based on a narrative poem
that every school child in Poland would have had to read, and would have known.
It was an interesting exercise in the practical problems of cultural and
national difference, and I learned something of the extent to which common
parlance for the principal audience of a film might remain virually unreadable
to another audience.