5 & 4. Jeanette & Therese (Vampire: The Masquerade)
It is impossible to talk about one without the other, and the reason for it is spoilerrific if you've never played Vampire: The Masquerade Bloodlines you've been warned. Jeanette is a wild one, she dresses in a fetish schoolgirl uniform with pigtails and a liberal amount of sloppy eyeshadow on her face, and immediately flirts with you quite suggestively from the get-go. She owns the local club in Santa Monica with her sister. Meanwhile, her twin sister Therese is the complete opposite. Formal and mature, she wears a classy suit, glasses and her hair fixed in an updo. She's well educated and polite, good qualities to have to be the Prince of any city. Later on they finally reveal to be one and the same vampire, and you learn that she or rather, they, are of the Malkavian race, vampires of addled minds, which makes them quite possibly the most fun breed to play as and the most entertaining to talk to. Their clearly split personality is not all that you'll remember about Jeanette and Therese; upon learning about their secret they reveal their sad backstory to you, which I will not go into, and depending on how you play your cards, one might kill the other or you may get the happy ending to their tale, when they finally agree to coexist peacefully.