What American actor actress does the best British accent?

There are many American actors and actresses that do an excellent job with British accents. They include:

- Meryl Streep

- Gwyneth Paltrow

- Daniel Day-Lewis

- Helen Mirren

- Kate Winslet

- Christian Bale

- Hugh Laurie

- Robert Downey Jr.

- Renée Zellweger

- Emily Blunt