Because you like Leonard Hofstadter in The Big Bang Theory
Smart and sensitive Sam Winchester tried to escape the family business, but ghosts have a way of haunting you. See them in Supernatural.
His murderous megalomania aside, Loki is quite charming. Just don't mention his strapping older brother; he's a tad jealous. See them in Marvel Cinematic Universe.
Brilliant, violent, and only a little insane, the Joker doesn't listen to anyone except the voices in his head. See them in DC Extended Universe.
Ciel Phantomhive is a haughty teenage nobleman who doesn't suffer fools gladly. See them in Black Butler.
Hiccup Haddock III may be the only Viking nerd in recorded history. See them in How to Train Your Dragon.
Phoenix Wright is an easygoing defense attorney who is rarely defensive. See them in Ace Attorney Series .
It's certainly easier to get great footage of crimes when you can guarantee they'll happen. See them in Nightcrawler.
Harry Mason has been told that he worries too much, that he's a little paranoid. But he just wants to protect what he loves. See them in Silent Hill.
Steve Stifler is more than just a dude with a hot mom. He's also rude, profane, and obnoxious. See them in American Pie.