4. Miranda Lawson
Miranda is more than just a pretty face. A tough-as-nails Cerberus officer, Miranda was the ultimate designer-baby. Every inch of her was designed by her father, using his seemingly unlimited source of funds to craft for himself the perfect daughter so that she might better stake humanity's claim in the universe. Her loyalty mission in Mass Effect 2 to save her sister really changed the character of Miranda for me, and in 3, when her conflict with her father finally comes to a head, it's a story we are totally invested in. Because we, much like your Shepard if he's got any wits about him, have been smitten by Miranda Lawson. Much, much more than a pretty face.