Seven of Nine, portrayed by the staggeringly beautiful and voluptuous actress Jeri Ryan on Star Trek: Voyager, was originally a human (Annika Hansen) who was assimilated by the Borg at an early age. Rescued by the starship Voyager, some 82% of her cybernetic implants were removed, but she retained the ability to sense nearby Borg activity. Seven of Nine was definitely the hottest human/borg hybrid around, while Jeri Ryan is one of the most gorgeous human females on Earth. We would fall for her nine out of nine times.
T'Pol, portrayed by beautiful actress Jolene Blalock, from Star Trek: Enterprise, is another excellent Halloween character choice. She is the hottest Vulcan in the galaxy, and arguably one of the sexiest females, of any species, ever to appear in the various Star Trek series. Her semi-nude scenes with fellow crew member Charles Trip Tucker were perhaps the most titillating to date in Star Trek.