On the cult show Buffy the Vampire Slayer, a group, consisting of Buffy and her friends, that fights evil and quips way more than necessary. First referred to as such by Xander as a joke, because the gang sorta solves mysteries, like Scooby Doo and co. The core Scoobies are Buffy, Xander, Willow and Giles; they remain in the group throughout the entire series. Honorary/temporary members include Anya, Tara, Dawn, Cordelia, Oz, and i guess Angel, Spike, Faith, Andrew, Jenny Calender, Wood, and dumb-ass Riley. Hon/temp members are this because they either died (shot through the heart, neck snapped, sliced by a Bringer) joined further into the show (i.e. became someone's girlfriend, were taken hostage, were created from living energy into a person, shit like that), left further into the show (as in had to control werewolf urges, had a hissy fit and flew away on a helicopter), turned evil (i.e. lost soul after moment of true happyness, lost love of life and went psycho, just kinda turned into an uber-bitch), switched to Angel the Series, or quite possibly a combination. Most everyone has a dark side/dark past, and they rarely all get along perfectly, and sometime they screw up, but they're Scoobies :)
"Yeah, I guess the Scooby Gang changes around a lot."
"Time for a Scooby meeting."
"You're the cutest of the Scoobies with your lips as red as rubies and your firm yet supple- tight embrace!" --Xander about Anya in Once More, With Feeling
"Don't tell me we're Scoobies." --a scathing Spike on Angel the Series