Subverted by El Goonish Shive; Diane fits the stereotype perfectly, but the setup turns it inside out. First, we see her as a "Mooching Tease Pimp" and Nanase keeps brushing off her attempts to get her into the Girl Posse. Then, Diane does one Sherlock Scan and is shown to be caring, implying that it's Jerkass Fašade. She seemed to be the most shallow and mundane character around, but now we can only guess who and what she is. It is almost certain is that she's not a magic-user.
Subverted by Footloose; Sparkle is very intelligent and somewhat Genre Savvy. She still gets her comeuppance though.
Subversion: In Penny and Aggie, Penny is a popular girl, and seems like an Alpha Bitch at first (in contrast to the independent-minded Aggie). As the story progresses, however, Penny turns out to be a decent, observant, intelligent person, with most of the conflicts between her and Aggie being initiated by the latter.
On the other hand, Carrie of Loserz is the epitome of this trope, or is at least trying to be. See here.
Charlotte Peechi from Annyseed. She displays all the common character traits, yet later, it is revealed that she's not the most popular girl in the school and hasn't exactly been spoiled by her parents. Will she get her comeuppance? All will eventually be revealed.
Felicia Laine in Ozy and Millie fits most of the characteristics of an Alpha Bitch, despite being in elementary school. In subversion of the trope, however, she's not stupid (as much as she acts the part), nor does she have any attraction to the strip's Jerk Jock Jeremy (indeed, they've never even met). Her infatuations are mostly directed at the members of boy band du jour.
You'd think that with cheerleaders as protagonists, Cheer! would be free of Libbies. You'd be wrong.
In Blip, Mary is a narcissistic, shallow, vain robot. On at least two occasions, she's been accused of using her Alpha Bitchiness to mask insecurity. Notwithstanding, she does seem to care about K and her friends. Maybe. At the start of the comic, she and K had a nasty falling-out, and refused to speak to each other for years. Mary makes the first reconciliatory gesture, and the two proceed to immediately bury the hatchet.
Though a minor character, Julia Greenhilt is clearly the Alpha Bitch of her magic school in The Order of the Stick, complete with two tagalong friends with whom she gossips about other students' clothing choices.
In the Scary Go RoundSpin-OffGiant Days, where Esther de Groot goes to university, she meets three former head girls, each of whom was probably the Alpha Bitch back at their respective schools. Although instead of (or perhaps "in addition to") cheerleading, each of them knows a specific style of martial arts.
Bridges features head cheerleader Lana, who is controlling of her squad to a borderline psychopathic level.
Lulu Cthulhu features three of these who have undertaken the mission to make all the losers feel accepted at Valentines' by giving chocolate to losers. They genuinely don't seem to understand why being singled out as losers doesn't make people happy.
Princess Pi has Sam, Alex, and Butch, also known as the Totally Nazis. The story "Princess Pi vs. The Alpha Bitch" even uses this trope's name in reference to Sam, although Pi expresses confusion about the term's meaning.note She thought it referred to a canine Sesame Street character who helped children learn about letters.
Zodiac Blues gives us Lia, who calls even her boyfriend a 'loser'.
Homestuck has Vriska, who uses violence, intimidation and actual mind control to secure her status as a high-ranking and powerful player in both SGRUB and Flarp. However, she is shown while talking to John to have some regrets over her actions, putting her outside of the typical Alpha Bitch trope.
Drowtales demonstrates this at least in the early chapters in the form of Chrys'tel Vel'Sharen and her Five-Man Band. Though it should be said that she has turned traitor to her clan, and the rest of the 5 man band has either joined an enemy faction, died, rebelled or is just plain abandoned.
Dreamkeepers Prelude gives us Stacephanie and her Girl Posse Triffany, Ashleybelle, and Leslieanna. They focus on belittling Lilith, but will turn on each other if necessary.