Let's see, where to start. Some asshole solves this ancient puzzle box thing that unleashes the Cenobites, sadomasochistic demons from Hell, who subject him to unbearable pain and unspeakable pleasure (or whatever) and splatter his body to bits. Later, the asshole's brother and his family move into the asshole's house, but it turns out the asshole is still somehow alive and trying to reform his body. Using the brother's wife (who he was having an affair with), men are lured back to the house to be killed so the asshole can harvest their blood and organs to rebuild his body.
I'm not really sure that Hellraiser is a good movie in terms of story, or characters, or structure, or anything like that. Even the interesting theme it raises (the whole pleasure/pain thing) isn't explored, it's just window dressing for the special effects.
But what effects they are! I must admit, I'm a big fan of the first two Hellraiser movies, mostly because they have such a wicked, grotesque visual imagination. Clive Barker's gothic vision of unfathomable horrors never comes to fruition in the story; the Cenobites just seem like weird dudes with awesome make-up and not the all-powerful evil they are supposed to be, and the audience never really gets a taste of the boundless pleasures and pain their world is supposed to encompass. Yet it does come across somewhat in the visuals, especially in the special effects. It's all of the skinless bodies, dismemberment by chains, hammer murder, strange creatures, etc. etc., that make these movies kinda awesome.
I make it sound like a geek show, but Hellraiser's not really trying to rub your nose in filth as much as it tries to delight you with its wicked excesses. It may not have much in the way of narrative interest, but it's a feast for the senses for those of us who like this sort of thing.