Because you like Ryan O'Reily in Oz

Leone Montana is a fearless hitman with a surprisingly sensitive side. See them in Leon: The Professional.

This power-hungry Time Lord calls himself the "master of all." Bonus: he has 13 lives. See them in Doctor Who.

You wouldn't know it by looking at her, but beneath Sheila Jackson's sweet, motherly exterior lies a sex addict. See them in Shameless.

Sydney Bristow is a kick-ass double agent on a mission for revenge. See them in Alias.

It's impossible to say whether Winifred Burkle is cuter than she is smart, or vice versa. See them in Angel.

In Ziva David's world, you grow up fast; you don't have a choice. See them in NCIS.

Phoebe Halliwell is a bestselling author and martial arts master with power of premonitions. See them in Charmed.

Kilgrave is a domineering, abusive boyfriend. Then, add in the power of mind control. See them in Marvel Cinematic Universe.

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.

Anya Jenkins has a real harsh bark to go with her demonic bite. See them in Buffy the Vampire Slayer.

Although she is underestimated, Lagertha never fails to prove her worth as both a warrior and a mother. See them in Vikings.

Helena is a mentally unstable, childish, and completely merciless. And most of all, she's an unstoppable killer. See them in Orphan Black.