Video Reviews : ****Excellent***Good**Fair*Poor : <i> Recent videocassette releases, reviewed by Times critics.</i> : Movies

*** “Someone to Watch Over Me.”

RCA/Columbia. $89.95. 1987. R.

Ridley Scott (“Blade Runner”) again proves himself a dazzling visual stylist. The director and his collaborators fashion a Gershwinesque New York of swooning urban beauty and violent jazzy undercurrents; they almost leave you drunk on glamour. But in this romantic thriller about a handsome, married cop (Tom Berenger) who falls for the murder witness (Mimi Rogers) he is assigned to protect, romance outclasses suspense--the villain is a dutiful psychotic sacrificing himself to the service of the plot. Scott’s attempt to collide the blue-collar and chi-chi worlds of the lovers weakens after a brilliant double opening, and his story lacks surprise and depth.