3. Phyllis Dietrichson - Double Indemnity
In the 1944 version of Double Indemnity, Barbara Stanwyck portrays a wintry-cold Phyllis Dietrichson. Phyllis persuades insurance agent Walter Neff to help her kill her husband to collect the insurance money for his death, which is double the money for accidental death in accordance with the double indemnity insurance clause. Phyllis has taken on several hidden roles in her life under the pretenses of love (when dating her step-daughter's boyfriend behind her daughter and enamored accomplice's back) and aid (when killing her husband's last wife and stepdaughter's mother while she was serving as the woman's nurse). Having killed both her step-daughter's parents and attempted to kill Neff, after already betraying his affections for her as a tool for her advantage, Phyllis might be the most heartless femme fatale to ever strike the movies. On that note, did I mention she's based on a real murderer named Ruth Snyder?