Because you like Marius in Les Miserables
Firo Prochainezo is swept up in a world of mysterious women, alchemists, and rumors of a wine that makes it drinkers immortal. See them in Baccano!.
Greg Heffley will be famous someday, but now he's stuck in class with morons. See them in Diary of a Wimpy Kid.
Kathryn Merteuil may be a vain sociopath, but you won't be able to look away. See them in Cruel Intentions.
Morticia Addams hates anything bright and cheery and loves all things ghoulish, ghastly, and violent. See them in The Addams Family.
Emma Woodhouse knows what's best for everyone else. Just don't try to tell her what to do. See them in Emma.
Linda Belcher doesn't prescribe to what society deems as "normal." She narrates her life through song, much to the alarm of everyone nearby. See them in Bob's Burgers.
Cisco Ramon is a proud, enthusiastic member of a superhero support team. See them in DC Extended Universe.
Wanderer is a Soul, a parasite sent into a host to take over their body, extracting information from them and colonizing their species. See them in The Host.
Sookie St. James is a klutzy and perfectionist chef who's always there for her friends. See them in Gilmore Girls.
A soulful bass player, Nick O'Leary can't stop sending breakup CDs to his ex. See them in Nick and Norah's Infinite Playlist.
Eugene H. Krabs is a greedy restaurant owner who won't let a dime out of the reach of his claws. See them in SpongeBob SquarePants.