Because you like Sideshow Bob in The Simpsons
Gomez Addams fills his days with ghoulish and ghastly forms of recreation, enjoying life and all its pleasures to the fullest. See them in The Addams Family.
Toby Cavanaugh has trouble avoiding being manipulated. See them in Pretty Little Liars.
Tina Goldstein is better at getting the job done than following the rules. See them in Fantastic Beasts and Where To Find Them.
His name is Inigo Montoya and whoever killed his father should be prepared to die. See them in The Princess Bride.
Marshall Eriksen is a lawyer in love who is enjoying life. See them in How I Met Your Mother.
Madman, murderer, or musician? No one knows the Phantom behind the mask. See them in The Phantom of the Opera.
Fate has forced Amuro into the terrors of war, and he must use the Gundam and all of its power if he is to make it out alive. See them in Mobile Suit Gundam Series.
Give in to the dark side with vampire Lestat; it's more fun. See them in Interview with the Vampire: The Vampire Chronicles.
Keeping your cool is just as useful in the underworld as in war, and Michael Corleone is stone-cold. See them in The Godfather.
A devoted butler, Alfred Pennyworth is both a fiercely protective guardian and a lethal gunman. See them in Gotham.