3. Theres Something About Mary (1998)
If I could only pick a single image from Cameron Diaz's career on-sceen and label it iconic, I'd have to say that it's the one pictured above. The famous "hair gel" gag from the Farrelly Brothers' note-perfect gross-out comedy There's Something About Mary. Indeed, here, there's something about Diaz - her effortless likeability combined with that slyly spot-on 'straight-man' comic timing - that sees her shine, even in such a sizeable cast of characters. It's clearly not her most dramatic role - There's Something About Mary is about as vulgar and brash as The Farrelly's get - however in it, Diaz continues to deliver that consistently solid performance which invariably allowed her to continue climbing the ladder to Hollywood superstardom.