'Hairspray' is an incredibly catchy, upbeat, and loveable musical. It's big-hearted and sweetly nostalgic, arch but emotionally sincere. As a piece of cinema, it's visually very imaginative and stands on its own two feet: this is by no means just a 'film version' of the stage show.
The cast is fantastic, especially at the younger end - Nikki Blonsky has astonishing presence and conviction and owns every scene she's in, which is most of them - but John Travolta, Queen Latifah and Christopher Walken are also very fine. Travolta could have been awful, but ultimately pulls off his role, and seeing Walken play sweet and supportive is in some ways even more disturbing (but in a good way) than watching him play scary.
The Blu-Ray transfer is pin-sharp, the extras are bountiful and at Amazon's current price (a tiny fraction of the RRP) it's a bargain you should not even try to resist. 'Hairspray' is happiness in an aerosol can.