By Lawrence O'Toole
October 15, 1993 at 04:00 AM EDT

If they’re out of Sidekicks, try renting these alternatives:

* The Karate Kid (1984, Columbia TriStar) Ralph Macchio is the weakling who becomes a pillar of inner and outer strength under the tutelage of Pat Morita. A-

* It Should Happen To You (1953, GoodTimes) Like Sidekicks‘ Jonathan Brandis, Judy Holliday plays someone living out a Walter Mitty-ish daydream: a woman who pines to see her likeness on a New York City billboard. She gets her wish, and her answered prayers prompt laughs rather than the proverbial tears. A-

* Crusoe (1988, Virgin Vision) Beautiful to behold, the latest and most updated version of the Robinson Crusoe tale stars Aidan Quinn as the main man and Ade Sapara as the ultimate sidekick, Friday. B