2. Seven Of Nine
I've never been a real fan of Star Trek: Voyager, but the end of Season 3 introduced a new character that made me appreciate it a little more: Seven of Nine. Why would anyone want to resist this Borg? In all seriousness, IMDB.com rated this episode as number one of the top twenty episodes of the series. This was a pivotal moment for the Star Trek franchise: not only did it see the inclusion of a Borg as a member of a Starfleet crew (solidifying the inclusive ideal that the Federation's doors are indeed, open to anyone), but that there was more than just the promise of defeat that lay in store for this enemy: there was also the possibility that they could become allies as well. The episode was titled "Scorpion", and involved the idea that both the Federation starship and the Borg both had a mutual enemy. The only way past this common foe was by trusting each other. Trust includes a degree of humility and Captain Janeway swallows her pride a little as well as making a tactical decision to ally with the Borg, represented by Seven of Nine. The Borg, likewise have to curb their perpetually superior attitude, and accept the aid of the inferior race they have terrorized ever since Q's forced introduction in Star Trek: TNG. Now they are the defender that must resist the more powerful Species 8472 to ensure their survival. Now they understand that resistance is not futile ... and they leave a separated Seven of Nine from the Collective with Voyager to understand what it is to be human. ... And for us to enjoy Jeri Ryan's performance as Seven of Nine, who I attribute rescuing this series from the graveyard of obscurity. Well done, Jeri.