Because you like Leonard "Bones" McCoy in Star Trek

Waylon Smithers would do anything for his boss, and would love to do a few things *to* him. See them in The Simpsons.

Christine Palmer is a great surgeon and an even better friend. See them in Marvel Cinematic Universe.

Dolores Umbridge keeps her villainy hidden (albeit poorly) behind a sheen of sugary pink politeness. See them in Harry Potter Series.

A devoted butler, Alfred Pennyworth is both a fiercely protective guardian and a lethal gunman. See them in Gotham.

Leonard Hofstadter is the normal one among his scientist friends, though in fairness that's a low bar. See them in The Big Bang Theory.

Macbeth was probably named "Most Likely to Kill His Rivals" in his senior yearbook. See them in Macbeth.

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

Beneath Arthur's brash demeanor lurks the heart of a compassionate future king destined to unite the five kingdoms. See them in Merlin.

A Silurian lizard woman, Madame Vastra has a penchant for puzzles and interspecies romance. See them in Doctor Who.

Davos Seaworth is steadfast, intelligent, and trustworthy, which are hard traits to find in a place like Westeros. See them in Game of Thrones.

Will Turner is an earnest, lovelorn blacksmith's assistant with an adventurous spirit. See them in Pirates of the Caribbean: the Curse of the Black Pearl.

Joe West is overprotective and secretive when his children are involved. See them in DC Extended Universe.