Because you like John Blutarsky in Animal House
Olive Hoover is an irrepressible child beauty queen (or would-be queen) who doesn't play by your rules. See them in Little Miss Sunshine.
Shawn Hunter may be a bit of a rebellious bad boy, but he has a heart that's pure gold. See them in Boy Meets World.
Ted Logan wants to party on, but if doesn't get an A+ on his history presentation, he'll flunk out and be sent to a military school in Alaska. See them in Bill & Ted's Excellent Adventure.
Emma Frost's superpower: transforming her body into an unbreakable diamond. See them in X-Men Series.
Marlin navigates through shark-infested waters, angry anglerfish, a jellyfish bloom and hungry whales to search for his son. See them in Finding Nemo.
Samantha Jones is a try-sexual who'll try anything once. See them in Sex and the City.
Chef is a swinging bachelor and former R&B singer with a leopard-skin upholstered couch and some great stories. See them in South Park.
Chuck Bartowski is a sweet, laid-back electronics store/top secret government employee. See them in Chuck.
Blunt but anxious, Gretchen Ross bonds most easily with those who have lived tough lives like she has. See them in Donnie Darko.
James Gordon happens to be the one guy in Gotham City with proper morals who doesn't also run around in a cape. See them in DC Extended Universe.