Keira Knightley is called the most miserable celebrity in the country.

I think Evangeline Lilly has the title in America.
Daily Mail:
She is fast becoming the most miserable celebrity in the country.
In recent months, Keira Knightley has seemingly taken every opportunity to bemoan her life of fame and fortune.
The multi-millionaire screen beauty's latest list of annoyances includes red carpets at her world premieres, being approached by members of the public and having her picture taken.
She has said she hates being criticised for being too thin, winces watching herself on screen and even wants to give up the celebrity whirl altogether because she dislikes what fame has brought her.