2. Seven of Nine - Star Trek: Voyager (1997)
I'll admit I'm not much of a Seven of Nine fan, but even so I must recognize the genius of the character. Beginning with Hugh, the temporarily captured Borg from Star Trek the Next Generation, the Star Trek franchise realized it had a winner of a character in a reformed Borg. Seven of Nine on Star Trek: Voyager is the culmination of that realization. Known simply as Seven of Nine or just Seven, this former Borg drone was born as a human named Annika Hansen. Assimilated at a young age, Seven was eventually severed from the Borg collective and slowly learned to adapt to her individuality much as Hugh had begun to adapt in STNG. Most of Seven's Borg cybernetic implants were successfully removed by Voyager's doctor, allowing her to regain much of her human appearance. Seven of Nine often performed a role similar to Data and Spock aboard Voyager. Lacking an effective foil for Captain Janeway in Voyager's early episodes, Seven filled the role admirably in later episodes, and often introduced conflict in the previously-stale television series.