I haven't seen National Lampoon's Christmas Vacation in a long time, but I am familiar with the Lampoon Vacation format. The whole family gets together and the father, Mr. Griswold, tries to make whatever vacation they are going on perfect. The Spirit of Christmas (is the)Present(s) is celebrated by practically everyone, so it's not about Jesus or God as it is about each other. We spend a lot of money taking one day to show how special we are to each other, at least, collectively we do, and that's what the Christmas vacation is about too- it's about the love the family has for each other.
National Lampoon's Christmas Vacation can never be considered the best Christmas movie of all times for two reasons. Number one is its star, Chevy Chase. He's just not very funny, not even awkwardly funny. Second, the major award for the best Christmas film of all time is owned by A Christmas Story and always will be.
National Lampoon's Christmas vacation is a horrible movie! The best Christmas movie of all time is Miracle on 34th Street. The original or the re-make, your choice! That movie is touching, well written, funny, and relevant. The National Lampoon movie is just Chevy Chase falling all over himself. Again and again.
National Lampoon's Christmas Vacation is a great Christmas movie but it is not the best of all-time. That title belongs to A Christmas Story. This is not opinion, but a fact. A Christmas Story is shown all day long on Christmas and is one of those movies everyone has watched a million times.
According to a poll in 2012, "A Christmas Story" is the most popular Christmas movie, followed closely by "It's a Wonderful Life". "A Christmas Carol" (any version) was the third most popular, followed by "Christmas Vacation". Of course this isn't scientific at all and it's really a matter of personal taste. My favorite for the last few years has to be "Elf" (which was way down the list in popularity).