Count me among the millions of Christmas Vacation viewers who hated Todd and Margo, Clark's neighbors, despite the fact that they really don't do anything wrong other than exist as terrible yuppies. As Megcentric points out with a clever diary written from Todd's point of view though, they really do get the short end of the stick in the movie. In fact, the Griswolds pretty much ruin Todd's entire life.
While I might not be able to agree that the two are actually unsung heroes, they certainly do get pretty screwed over during the film.