Because you like Nilin Cartier-Wells in Remember Me (Video Game)
John Watson is haunted by his past (who isn't) but he's starting to branch out with some help from a world class detective. See them in Sherlock.
Sheldon Cooper is brilliant in every way except, well, interacting with any human being. See them in The Big Bang Theory.
L is enigmatic, child-like, and one of the smartest people in the world. See them in Death Note.
Barry Allen is a nerd, forensics expert‚ and superhero with supersonic speed who is determined to solve his mother's murder. See them in DC Extended Universe.
His murderous megalomania aside, Loki is quite charming. Just don't mention his strapping older brother; he's a tad jealous. See them in Marvel Cinematic 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.
What Ron Weasley lacks in motivation and book smarts, he makes up for in loyalty and street smarts. See them in Harry Potter Series.
After surviving consecutive fights-to-the-death (damn you, President Snow!), Katniss Everdeen is thrust to the front lines of a real war. See them in The Hunger Games .
He's an eccentric pirate making it up as he goes along. He's Jack Sparrow, savvy? See them in Pirates of the Caribbean: the Curse of the Black Pearl.
A daring conman, Flynn Rider is so charismatic that you might not mind when he steals from you. See them in Tangled.