No modern actress has an aura approaching Tilda Swinton's. Slim, pale and towering, keen of features and intellect, she invests her characters with an imperious mien and brings a fearless commitment to all her movies, whether big (she's the witch in the Narnia films and won a Supporting Actress Oscar for Michael Clayton) or avant-small (like Sally Potter's Orlando, in which she played a 400-year-old androgyne). Always willing to defile herself for her art, she will try anything and make it work. This year Swinton, 50, moved in the opposite direction: instead of down and dirty, she went regal and sensuous. To play the Russian-born wife of a Milanese plutocrat in Luca Guadagnino's swoony extramarital romance, she learned to speak Italian with a Slavic accent and located the passionate will beneath Emma's studied elegance. Another triumph for the daring, commanding, supreme film actress of our time.