Because you like Martin Riggs in Lethal Weapon
With a brilliant mind, an insane level of confidence, and a penchant for drunken dancing, Cristina Yang is a force to be reckoned with. See them in Grey's Anatomy.
It is a truth universally acknowledged that Elizabeth Bennet doesn't suffer fools or prideful men. See them in Pride & Prejudice.
When the going gets tough, Rick Grimes gets tougher. It's a very useful trait when the world goes to hell. See them in The Walking Dead.
An exuberant prankster, Naruto Uzumaki craves acknowledgement of any kind. See them in Naruto.
Charles Xavier is a telepath who believes mutants and humans are both good at heart and can live in harmony. See them in X-Men Series.
Aragorn is the one true king, a title he is too humble to accept. See them in The Lord of the Rings.
People think that because Tris is small, or a girl, or a Stiff, she can't possibly be cruel. But they're wrong. See them in Divergent.
Howl puts the "tortured" in tortured artist. He just wants to be recognized for his work, but no one wants to trust a boy that sorta looks like a bird. See them in Howl's Moving Castle.
Orphan Bruce Wayne has a tortured soul, but he's trying his best to weed out corruption. See them in DC Extended Universe.
When the Sorting Hat touched Draco Malfoy's head, it placed him in Slytherin, a house that has turned out more dark wizards than any other. See them in Harry Potter Series.