Because you like Drusilla in Buffy the Vampire Slayer
Tina Goldstein is better at getting the job done than following the rules. See them in Fantastic Beasts and Where To Find Them.
Quinn Fabray can become a monster when there is something she wants. See them in Glee.
CIA operative Carrie Mathison is on a self-assigned mission to follow a lead, whether it be the truth or just her delusions playing tricks. See them in Homeland.
Despite the war-torn world around him, Mal Reynolds still holds onto the shred of hope that life can be more than just living another day. See them in Firefly.
Don't tell anyone Kate Austen was under arrest when the plane crashed. See them in Lost.
Part archaeologist, part philosopher, part politician, Jean-Luc Picard is an unashamed intellectual who runs a tight ship. See them in Star Trek: The Next Generation.
A powerful priestess, Melisandre is shrouded in mystery and lots of red. See them in Game of Thrones.
Helena is a mentally unstable, childish, and completely merciless. And most of all, she's an unstoppable killer. See them in Orphan Black.
The party never really ends with Penny Lane, a rock-worshipping groupie who is refreshingly self-aware and free-spirited. See them in Almost Famous.
Eric Forman's interests include smoking weed, collecting Luke Skywalker memorabilia, eating Fatso burgers, and making his dad mad. See them in That '70s Show.
As a doctor-in-training, John Dorian should have his head in the game. But most of the time, it's in the clouds. See them in Scrubs.