Oscar-winner Nicole Kidman is certain she is yet to deliver a truly great performance, and believes her best work is still to come. The Australian actress, who won an Academy Award for her role in The Hours in 2003, began her career determined to star in a genuinely great film and believes she is still to deliver a really exemplary rendering of a role. She tells Britain's Seven magazine, "I had huge expectations. You start out with big dreams and I mean, big dreams artistically. You want to work with the greatest living directors, make a great movie. I want to make a great love story, I wanted to make a great epic and then you realise that the truth of it is that it's so hard to make a great film. It's hard to get a great role. "Those big expectations change to realism pretty quickly. But what's never changed is my desire to work with great directors and to find projects that push me out of my comfort zone and keep my alive. "I still don't think I've done my best work... I want somebody to discover a great performance in me. I still don't think I've given a great performance and I'm waiting." The actress' latest film, Grace of Monaco, was panned by critics when it premiered at the Cannes International Film Festival earlier this month (May14), and over the weekend, Kidman revealed she turned down the chance to play Hanna Schmitz in 2008's The Reader because she was pregnant with her daughter Sunday Rose. Kate Winslet went on to win a Best Actress Oscar for the role.