Diaz has shown us that she has a sense of humor before, like in comedic gems such as There's Something About Mary. Now this movie isn't exactly a "comedic gem", but there are enough laughs to make Bad Teacher a good comedy.
Diaz plays Elizabeth Halsey, a rude, self-centered, foul-mouthed junior high school teacher who took the job after being dumped by her sugar daddy and now finds herself in need of a serious boob job in order to woo a fellow teacher for his money.
Diaz's real-life ex, Justin Timberlake, just happens to be that fellow teacher. Mr. Scott Delacorte is a shallow loser who unintentionally (or intentionally) ends up in the middle of a feud between Diaz's Halsey and Lucy Punch's Amy Squirrel. Loser aside, Timberlake feels a little self-aware of his goofiness but still puts on a good performance.
The chemistry between Diaz and the hilarious supporting cast, made up of funny people like John Michael Higgins; The Office's Phyllis Smith; and Thomas Lennon, is undeniable and even adds a level of charm come the third act. Perhaps the best part about Bad Teacher is Jason Segel's performance as a gym teacher who actually enjoys life.
I have to admit that at times I found it difficult to root for a character who is so self-centered and even after the cliche third act "change of heart", I still didn't buy into the ending. However, I cannot deny how much I laughed at this movie and how much I like enjoyed the supporting cast.