Being able to do accents, as an actor certainly widens the scope of the amount of roles that you are able to do. For some actors, they seem to slip into a British accent with ease, but for others it's simply cringeworthy watching them try.
Alexis Denisof did a great English accent during his stint on Buffy the Vampire Slayer. Image: Wikipedia
Who do you think slips into a British accent and pulls it off, despite the fact that they don't actually herald from Britain.
I think Renee Zellweger, did a great job with Bridget Jones. Angelina Jolie in zlara Croft Tomb Raider; also Mickey Rourke as Martin Fallon in A Prayer for the dying (Irish); Johnny Depp's in Pirates, was capable and apparently Forest Whittaker's accents are all spot-on. Elijah Wood in Lord of the Rings too, deserves a mention. On the other side of the coin, Welsh actor Matthew Rhys can do a great American accent! c&c