Some franchises decline gradually, while others fall right off the table. The Vacation series followed the latter trajectory. Not that National Lampoon's Vacation (1983) was a shining example of subtlety, but its sequel, National Lampoon's European Vacation, tosses aside any semblance of restraint. It starts with the plucky Griswolds competing in a game show that forces them to dress up in pig costumes, and never recovers. The Griswolds are meant to embody the vulgar tackiness of the typical tourist, all the more square while rubbernecking Europe, but what made them lovable at first introduction was their sense of familiarity. Here, that's been replaced by a sense of repulsion. Personnel changes behind the scenes don't really explain it -- coming off Fast Times at Ridgemont High (1982), director Amy Heckerling should have been a fine successor to Harold Ramis, and Robert Klane couldn't have poisoned the well too much working alongside John Hughes, the original's sole screenwriter. Chevy Chase and Beverly D'Angelo are back in the same form. So it must be the thoroughly disagreeable choices to play the Griswold children -- Jason Lively and Dana Hill -- who sink this enterprise so completely, because this is the worst of the four Vacation movies, and the only one with them in it. It's also the only one where the Griswolds topple Stonehenge by backing into it with a rental car -- thank heavens for small favors.