Because you like Walter Bishop in Fringe
Frodo might have carried the ring, but Samwise Gamgee carried the ring bearer. See them in The Lord of the Rings.
Kara "Starbuck" Thrace will beat you in cards, drink you under the table, then fly circles around you in her fighter plane. See them in Battlestar Galactica.
Jack Bauer is a terrorist fighter who is scared of nothing and no one. The clock is ticking! See them in 24.
Clarice Starling is patiently working with one serial killer to stop another. See them in The Silence of the Lambs.
Kilgrave is a domineering, abusive boyfriend. Then, add in the power of mind control. See them in Marvel Cinematic Universe.
Olive Hoover is an irrepressible child beauty queen (or would-be queen) who doesn't play by your rules. See them in Little Miss Sunshine.
A poised, stately man-out-of-time, Ichabod Crane typically faces the modern world with wry quip. See them in Sleepy Hollow.
Michael Scofield is no criminal, and he didn't get jailed by accident. See them in Prison Break.
A suave manipulator, Sebastian Valmont is valiantly fighting off a developing conscience. See them in Cruel Intentions.
Emma Frost's superpower: transforming her body into an unbreakable diamond. See them in X-Men Series.
Khan Noonien Singh is super strong, super smart, and out for revenge. He always seems to be two steps ahead of his enemies. See them in Star Trek Into Darkness.