Because you like Duke Nukem in Duke Nukem
Gene Belcher dreams of a future in the limelight, and he doesn't let his lack of talent hold him back. See them in Bob's Burgers.
The biggest nerd in high school, Bill Haverchuck is the biggest target for bullies. See them in Freaks and Geeks.
A scary monster on the outside, James P. Sullivan is really a softie on the inside. See them in Monsters, Inc..
With most of the people that Sango loved now gone, the only thing she wants is to kill the demon who destroyed her village. See them in Inuyasha.
Sarah Kerrigan is pretty much the Queen Bitch of the Universe. See them in StarCraft .
A reclusive introvert, Liz Sherman has a temper that's literally lethal. See them in Hellboy.
Eric Forman's interests include smoking weed, collecting Luke Skywalker memorabilia, eating Fatso burgers, and making his dad mad. See them in That '70s Show.
An alien, a time-traveler, and an esper are following Haruhi Suzumiya, who – unknown to herself – is a near-omnipotent reality warper. See them in The Melancholy of Haruhi Suzumiya.
It turns out Dracula's son Alucard has some pretty severe daddy issues. See them in Castlevania.