The story itself has a Gryffindor prep named Britney who is treated as an Alpha Bitch yet doesn't actually do anything bitchy. That's reserved for our hero, Ebony.
Sakura of Pretty Cure Full Color is a reformed Alpha Bitch. She gains her powers only when she fully accepts and befriends the people she used to make fun of.
Omemi Emiru from Futari Wa Pretty Cure Blue Moon is a variation on the concept. Rather than a beautiful blonde who stands out from the crowd (that would be Seira, a member of her Girl Posse whom she strictly keeps in line), Emiru has short green hair and Scary Shiny Glasses, and prefers to watch (and gossip) from the shadows. This understated approach has allowed her to obtain blackmail on nearly every girl in school, and by the time the story starts, they know it and bend to whatever she says. Considering one of the main themes of the story, eventually, this isn't enough for her..
Lisa Simpson of all people is cast as an Alpha Bitch in the Phineas and Ferb crossover fic "The Flynns Move To Springfield".
Cho Chang in A Very Potter Musical goes from being the Spoiled Sweet in the books, to still being Spoiled Sweet, but definitely having a lot of Alpha Bitchy traits. It's taken up to eleven in the sequel.
