NATIONAL LAMPOON'S VACATION: The Griswold family drives cross-country with an awesome tankful of laughter thanks to star Chevy Chase, writer John Hughes and director Harold Ramis. NATIONAL LAMPOON'S EUROPEAN VACATION: Europe won't survive Chevy Chase and American family vacationers. Howl as they trigger chaos all over a continent. NATIONAL LAMPOON'S CHRISTMAS VACATION: Make merry as the Griswolds - including a pack of rib-tickling relatives played by an ensemble of comedy favorites - strive to gift-wrap the "perfect Christmas." VEGAS VACATION: Hit the comedy jackpot with the Griswolds when their next stop is Las Vegas - and the jokers are at their wildest.