One of the darkest, macabre and gruesome films I´ve ever seen.
Rather brutal, sometimes really gory but with some exceptional ideas and a few cool horror masks (i.e. Pinhead's or Frank's after his first victim). But other things (i.e. Frank's resurrection, the destruction of the Cenobites) are really cheap made and some dialogs are just silly.
As a horror movie, I can't really give this more than a 4. As a movie in general, given when it came out and the character - Pinhead - and how iconic it is, it can have an 8. Watch it for the history and for a solid film from the late 80s. Don't watch it for horror - it's not that scary.