When Cartier USA turns 100, you better believe all the stylish A-listers will show up to celebrate. And celebrate they did. Anne Hathaway sported Jill Stuart, Rachel Weisz and Demi Moore chose Prabal Gurung, Kate Hudson wore Rachel Roy, and Eva Mendes opted for Azzaro. Oh, and of course they were all dripping in Cartier jewels. Which Cartier-sporting celeb is most Fab?