Forbes says Nicole Kidman is a highly overpaid actor. But then later they say that Russell Crowe is the most overpaid actor. Forbes measured the amount of movie revenue made per dollar of actor's salary:
I call "bunk" on this figure, though. All it is is the inverse of the actor salary taken as a percentage of movie earnings. It makes sense that top actors can take in 10-20% of a movies earnings (translates into the $5 to $10 shown above). So Russell Crowe's $5 may just mean that he really is worth 20% of movie revenues.