Because you like Sandy Cheeks in SpongeBob SquarePants
Driven and straightforward with high-technology parts, EVE was sent to Earth to see if it is habitable. See them in WALL-E.
A short-tempered guy, Bowser is determined to wreak havoc on the Mushroom Kingdom. See them in Super Mario Bros..
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.
This cannibalistic villain may be a loner, but Killer Croc doesn't have problems with self-confidence. See them in Suicide Squad.
Princess Bubblegum is brilliant and determined, but can display a nasty temper. See them in Adventure Time.
Velma Dinkley is all about getting results, not taking credit. She is the unsung hero of Mystery Inc. See them in Scooby-Doo.
Amy Farrah Fowler deserves sainthood for putting up with Sheldon Cooper. See them in The Big Bang Theory.
Waylon Smithers would do anything for his boss, and would love to do a few things *to* him. See them in The Simpsons.
Topanga Lawrence has been a put-together intellectual since basically the moment she could talk. See them in Boy Meets World.
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.