Because you like David Wooderson in Dazed and Confused
A believer in the pursuit of justice, Garrus Vakarian hates it when bad guys slip through the cracks of the bureaucratic justice system. See them in Mass Effect.
Philip J. Fry accidentally cryogenically froze himself for a millennium. See them in Futurama.
Quinn Fabray can become a monster when there is something she wants. See them in Glee.
Michael Bluth is the only sane person in a family of eccentrics. At least, that's how he thinks of himself. See them in Arrested Development.
She's mostly doom and gloom, but you'd get nowhere without Sadness. See them in Inside Out.
Morticia Addams hates anything bright and cheery and loves all things ghoulish, ghastly, and violent. See them in The Addams Family.
Shaggy might be a bit of a slacker, but his heart and his stomach are usually in the right place. See them in Scooby-Doo.
Velma Dinkley is all about getting results, not taking credit. She is the unsung hero of Mystery Inc. See them in Scooby-Doo.
Part archaeologist, part philosopher, part politician, Jean-Luc Picard is an unashamed intellectual who runs a tight ship. See them in Star Trek: The Next Generation.