Because you like Twilight Sparkle in My Little Pony
Ciel Phantomhive is a haughty teenage nobleman who doesn't suffer fools gladly. See them in Black Butler.
Usagi Tsukino may look like a lazy teen, but when Usagi conjures up her alter ego and calls her Sailor Scout team, no villain stands a chance. See them in Sailor Moon.
Deadpool thinks life is an endless series of train wrecks with only brief commercial-like breaks of happiness. See them in Deadpool.
Trying to get through school without being a burden to anyone, Tohru Honda stays cheerful despite her difficulties. See them in Fruits Basket.
A cursed pirate captain, Barbossa is greedy, vengeful, and surprisingly cheeky. See them in Pirates of the Caribbean: the Curse of the Black Pearl.
Don't tell anyone Kate Austen was under arrest when the plane crashed. See them in Lost.
Michaelangelo is an above-ground crime-fighter by night, and a pizza-eating, sewer-dwelling mutant ninja turtle by day. See them in Teenage Mutant Ninja Turtles.
Rick Sanchez is a gruff, alcoholic mad scientist, with the emphasis on "mad." See them in Rick and Morty.
Yuki Cross is a cheerful, funny, bold young woman with hidden insecurities. See them in Vampire Knight.
People make more sense to the hyper-logical Temperance Brennan after they're dead. See them in Bones.
Glenn Rhee somehow never loses his enthusiastic spirit – even in the middle of a zombie apocalypse. See them in The Walking Dead.