10. Julia Cotton - Hellraiser & Hellbound: Hellraiser II
Hands up everyone who always thought that the main character in Clive Barker's Hellraiser was Pinhead. It's not an unreasonable assumption, given Doug Bradley's Lead Cenobite (the only name he is given in the 1987 original) dominated the poster/VHS art, and became the focal point of the long-running (though frequently subpar) franchise that followed.
However, watch the original Hellraiser again and it becomes clear that it's not Pinhead, nor the top-credited Andrew Robinson who is the real lead: it's Clare Higgins' Julia. Dissatisfied by her marriage to Robinson's Larry, Julia fixates on her fleeting affair with Larry's brother Frank - so she's naturally alarmed to find Frank barely alive in the attic of the old Cotton house, having been torn apart by the demonic Cenobites.
At Frank's urging, Julia turns black widow seductress, luring men home and feeding them to her lover to help him regrow his human form. While she may be compelled by feelings of love, the ease with which she slips into serial killer mode is unnerving.
However, while Julia may be in some respects a sympathetic, tragic heroine in Hellraiser, follow-up Hellbound: Hellraiser II sees her turn 100% pure villainess; understandable, given she's spent a bit of time in Hell by that point.