Because you like Niles Crane in Frasier
Although Penny's friends have genius-level IQs, they regularly come to her for advice and insight. See them in The Big Bang Theory.
Fiona Gallagher wants to be able to give her siblings everything that they deserve because her parents aren't going to do it. See them in Shameless.
Ellen Ripley defines the word "badass." When she's not leading her crew on an interstellar voyage, she's slaying terrifying creatures. See them in Alien.
Gotham's unhinged Clown Princess of Crime will call you puddin', then punch you in the face. See them in DC Extended Universe.
Stuck in space, Ryan Stone will either make it back to Earth and have one hell of a story to tell. Or she will burn into the ether. See them in Gravity.
Her unhappy childhood has left her unsure of the existence of happy endings. Mary Jane Watson hides her pain beneath a joke and a smile. See them in Marvel Cinematic Universe.
It turns out the girl of your dreams just might have dreams of her own. See them in (500) Days of Summer.
You don't teach a class called "How To Get Away With Murder" without knowing a thing or two about getting away with things. See them in How to Get Away with Murder.
Sensual, wild, and with a penchant for controlled substances, Lily is a ballet dancer who isn't afraid to let loose. See them in Black Swan.
Deadpool thinks life is an endless series of train wrecks with only brief commercial-like breaks of happiness. See them in Deadpool.
Tom Hansen is a full-fledged romantic impatiently waiting for his love story. See them in (500) Days of Summer.