"Get in, loser, we're going shopping" might just be one of the most recited movie quotes of all time, and it was said by none other than McAdams in the 2004 comedy "Mean Girls." Cady Heron (Lindsay Lohan) is a new student at North Shore High School and struggles to fit in among the large student body that is divided by cliques. She connects with school outcasts Janis Ian (Lizzy Caplan) and Damian Leigh (Daniel Franzese), who warn her of the school's elite clique, the Plastics, consisting of leader Regina George (McAdams), Gretchen Wieners (Lacey Chabert), and Karen Smith (Amanda Seyfried).
When Cady develops a crush on Regina's ex-boyfriend Aaron Samuels, she hatches a plan with Janis and Damian to infiltrate the Plastics, ruin Regina's queen-bee reputation, and win over Aaron.
In "Mean Girls," McAdams is perfectly snobby and posh, making her role one that is constantly revisited nearly 20 years later.
