Because you like Jack Bauer in 24
Sydney Bristow is a kick-ass double agent on a mission for revenge. See them in Alias.
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.
Kara "Starbuck" Thrace will beat you in cards, drink you under the table, then fly circles around you in her fighter plane. See them in Battlestar Galactica.
After surviving a CIA mission that was supposed to kill him, ex-military man John Reese bets it all on a chance to redeem himself. See them in Person of Interest.
If this slick ad man doesn't like the conversation, he changes it—while drinking and smoking. See them in Mad Men.
John Locke is an eerily calm, confident believer in the magic of the island that gave him his legs back. See them in Lost.
Loyal to his family and associates and distrustful of anyone else, Tony Soprano is a good guy to have on your side. See them in The Sopranos.
A master manipulator, Frank Underwood has a tight grip on Washington DC. Plus who doesn't like having a leader who frequently tosses off Shakespearean asides? See them in House of Cards.
An undercover DEA agent, Max Payne is too focused on avenging the past to plan for the future. See them in Max Payne.
A gruff and hardened professional, Marcus Fenix keeps his emotions buried deep. See them in Gears of War.
Marv is a brutish but principled thug who'd be right at home on an ancient battlefield. See them in Sin City.
Much more than just "Coach Taylor's wife," Tami Taylor is making herself known in town as a caring, persistent guidance counselor. See them in Friday Night Lights (TV).