I found *National Lampoon’s Vacation* to be somewhat disappointing; I had expected it to be funnier. Still, I believe it's enjoyable enough to warrant a viewing. The final scene featuring John Candy likely influenced my rating. Chevy Chase carries the comedic weight as you would expect. I was hoping he would portray a more hapless and foolish character, with a simpler, drier style of humor. He’s certainly depicted as silly, but not nearly as much as the character should be. Beverly D'Angelo works well with Chase. The younger actors, including Anthony Michael Hall, are generally acceptable in their roles. John Candy, who appears later, has clearly done better work; Eugene Levy also makes a brief appearance.

Source on TMDB