Good cult classic which falls short of its goal 'Cry-Baby' is good film, up there with 'Grease', 'American Graffiti' and other films which depict teenage high-school life, cliques and the pop culture, fashions and music of the 1950s. 'Cry-Baby' is a good attempt to parody the romance of good girls and greasers as seen in 'Grease' and films with a similar focus.
However, I do use the word 'attempt' strongly here. The film suffers from a lack of well developed satirical jokes and parody of 50s high school movies and if more time and thought had been put into it, it could have so much better. The other main failing of the film in my opinion is that the plot is too awkward and rushed: I don't think Alison's grandmother could have let her hang out with greasers so easily and the sequence of the prison sentences and the conclusion goes way to quickly to make the film satisfying. The characters are also somewhat one dimensional and more scenes to let us get acquainted with them and show the tensions i.e. Alison and her grandmother and Alison and her square singer boyfriend would have made the film so much more enjoyable and believable. If more scenes had been filmed to cover these elements and the final release was about 2 hours, the whole movie would have been so much better.
However, aside from that, I do re-watch this frequently and it is still very entertaining.