Legally Blonde (2001)

A funny premise -- wronged ditz of a girlfriend manages to get into Harvard Law School just to spite her snobby ex -- turns into a dismayingly comedy-by-focus-group take on movies like Clueless and Election. We're meant to think that Witherspoon's perennially pink-clad sorority chick is smarter than she looks, but that seems even less likely than the idea that getting through Harvard (not to mention teaching there) is the real no-brainer.