Adaptational Heroism: Georgia's cynicism and Bratty Teenage Daughter tendencies are very much toned down in the movie, and she's a much more accepting and normal girl than her book counterpart (not nearly as funny though). It's very evident in her relationship with her parents: in the film she's close to them, while in the books she's repulsed by both, especially her father.
Anti-Role Model: Even readers in the book's age demographic have found her a complete brat (a lovable brat, but still a brat).
Break the Haughty: A few times. She has more love problems than any of the other characters.
Brilliant but Lazy: Georgia hates school and homework (really, she only cares about appearance, makeup, dating, boys etc.) but she is actually quite bright when she's willing to put in the work.
Cloudcuckoolander: She's hilariously silly, like pretty much everyone else in the books.
Deadpan Snarker: In spades. The books should be renamed "Georgia Nicolson's snarky confessions". She's the epitome of the First-Person Smartass narrator, and it's the main source of humor of the books. Sadly this trait is almost completely absent in the movie.
Dude Magnet: Robbie, Masimo, Dave the Laugh, Peter Dyer, Mark "Big Gob", her cousin James, her younger neighbor Oscar, the French guy who offers her a rose during a field trip...In short, she basically attracts every guy except the ones who are already paired with her friends.
High School Hustler: She is a rare female example, with her schemes at school and rebellious attitude towards teachers and authority figures.
Hollywood Dateless: Played straight in the first two books, then it kinda becomes the parody of this trope, with Georgia still complaining about her love life, despite having plenty of boys and love interests.
Lovable Alpha Bitch: Despite her attitude and shallowness, she's really not than bad. Even if she usually looks down on her unpopular schoolmate Pamela Green, Georgia defends her from the bullies Bummer Twins, and when they are finally expelled, it is because she (along with her friends) told the school authorities that they were the shoplifters instead of P. Green who they had initially framed.
Love Makes You Dumb: Often she acts this way when around a boy. See her interactions with Robbie.
Malaproper: Georgia has... her own unique approach with the English language.
Never My Fault: "Why does the finger of shame always point towards me?"
Unreliable Narrator: The book is entirely from Georgia's point of view, so a lot of things she says are rather... questionable.
Unsympathetic Comedy Protagonist: Very much so. She's loved by fans for being humorous, sarcastic, lovable and entertaining. She also happens to be vain, selfish, shallow, idiotic, whiny, petty, and rude.
Vitriolic Best Buds: With Jas. They insult each other a lot and fight in almost every book...they are still best friends.