Because you like Cookie Monster in Sesame Street
Once a loving family man, James Heller is now dark, damaged, and hell-bent on getting revenge. See them in Prototype Series.
Stuck somewhere between life and death, Talion is motivated by one thing only: vengeance. See them in Middle-earth: Shadow of Mordor.
Dutiful, composed, and aloof, Sun Bak is the fighting force behind her team of eight "sensates" who are telepathically linked. See them in Sense8.
It's hard enough fighting a war. But it's worse for Commander Shepard, knowing no matter how hard you try, you can't save them all. See them in Mass Effect.
Clary Fray's philosophy: dive into the supernatural underworld first and ask questions later. See them in City of Bones.
For the sake of science, Kurisu Makise will persevere no matter how deep into the dark secrets of the world she finds herself. See them in Steins;Gate.
It's hard to tell if Dean Winchester cares more about saving the world or his 1967 Chevy Impala. See them in Supernatural.
The brilliant and well-adjusted Ender Wiggin is being groomed for the next generation of military leaders to fight alien invaders. See them in Ender's Game.
Alison DiLaurentis believes you're always better off with a really good lie. See them in Pretty Little Liars.
David Wooderson has clocked in hundreds of hours cruising around town looking for fun. See them in Dazed and Confused.