Although the title seems to promise a "clashing cultures" film, East Side, West Side is really about life among Manhattan's café society. To be sure, the film includes a couple of "salt of the Earth" types and makes passing reference to differences in social status, but for the most part it's just trappings on top of this glossy and superficial but nonetheless enjoyable look at a difficult Park Avenue marriage. East/West's screenplay is a bit of a hodgepodge, pulling in elements of romance from here, murder mystery from there, comedy from somewhere else; it all coalesces, but just barely. While much of the story and dialogue is routine, it does have a couple of surprises, notably in the way James Mason's self-destructive attraction to Ava Gardner's lurid charms are presented. Its ending is also a nice change of pace; while Barbara Stanwyck will most likely end up with Van Heflin after leaving Mason, at the end of the film proper, she has left simply because her life with Mason is no longer meaningful or fulfilling, a brave choice for 1949. If East/West's screenplay doesn't really challenge its quartet of stars, they're still in top form and make the film quite entertaining. Even better are the "name" players in the supporting cast, especially Gale Sondergaard, who truly makes the most of a bit part. Even Nancy Davis turns in an impressive performance. Mervyn LeRoy's direction is smooth and assured, if not particularly inspired, making East/West a lot of glossy fun.