6. Anne Hathaway
If I'm honest, I genuinely believe that Anne Hathaway can tailor her performance to any role, perfectly embodying whatever the part asks for and expertly delivering a wide range of emotions, sometimes all in the same scene. Whilst Hathaway has been brilliant in many roles, not least The Devil Wears Prada or more recently Les Miserables, her performance as Selina Kyle in The Dark Knight Rises proves exactly how versatile an actress she really is, notably the scene in which she first meets Bruce Wayne, where she switches from a clumsy, ditzy maid, into a confident, seductive master thief in a split second, in what is also a perfect introduction for her character. This versatility would suit the role of Kate Middleton perfectly, with Hathaway able to deliver a pitch-perfect performance on every aspect of Kate's life, whilst capturing the hearts of the audience effortlessly, something Kate herself did long before the royal wedding came around. It also helps that Hathaway has, like other entries in this list, played royalty before, although in Hathaway's case it was in a much less serious performance in The Princess Diaries and it's sequel. An award winner and an Oscar frontrunner, it makes perfect sense that someone so talented would be high on the list of those casting this biopic, regardless of her American nationality.