Oprah Winfrey has regained her spot at the top of Forbes’s 2010 list of the world’s 100 Most Powerful Celebrities, after Winfrey slipped to second place last year. Pop queens Beyonce and Lady Gaga landed at #2 and #4 respectively, with Avatar director James Cameron sandwiched between them. Rounding out the top 10: Tiger Woods (whose, um, tumultuous past year apparently did little to diminish his influence), Britney Spears, U2, Sandra Bullock, Johnny Depp and Madonna. Meanwhile, Angelina Jolie, who topped the list last year, tumbled down to 18th place. While her fall is likely due to the fact she hasn’t released a major film in the last 12 months, Forbes has some guts for daring to mess with Angelina.