Watched with my wife on our first date at her house. Man we have probably watched it 50 times since, and have multiple inside jokes from it - the # of kimonos packed for the 36 hours in Philadelphia, the ability to talk or not talk for hours, basically everything Fred Willard says, all the kinds of nuts that CG can recite.
3 times in our marriage while at social events, I have made my wife spit out food or a drink when I take the line about going to see where the cream cheese is made that Eugene Levy's fellow terrier lover says at the beginning of the movie. She's walked up while I'm talking to someone and I've turned and said, "Honey, honey! They're going to Philadelphia to see where the cream cheese is made just like we've been talking about all these years!" she's always pissed off even though she's laughing.