Because you like Donna Noble in Doctor Who
The only defense Earth has against alien invaders are giant robots in the hands of pilots like Kaworu. See them in Neon Genesis Evangelion.
If Anna Liebert could remember her past, maybe she would know who she is. See them in Monster (TV Show).
Edward Kenway can be reckless and greedy, but he's learning that his ancient ancestry carries a noble burden. See them in Assassin's Creed Series.
When dealing with a half-demon partner and a world of violence, Kagome Higurashi has plenty of chances for her true courage to shine. See them in Inuyasha.
Hans Landa doesn't seem to have issues with Jews, but he hunts them because he's determined to do his job well. See them in Inglourious Basterds.
Impassive, overly literal, and a little short on people skills, Angel dedicates her life to enforcing the rules. See them in Angel Beats!.
An obsessive schoolgirl, Yuno has two sides to her personality, and both are equally unnerving. See them in The Future Diary.
Clank is the quintessential rational, intelligent robot sidekick. See them in Ratchet & Clank.
A jealous woman is dangerous. A jealous assassin woman like Elle Driver is even more so. See them in Kill Bill vol. 1.