There's a story about how, when they were casting the role of House, they went through everyone they could find and no one seemed to fit the bill... they wanted the "perfect American."
When Hugh Laurie came in to do his audition, he came in already "in character" and when he was done, the director commented on how perfect he was.
I would have loved to see their faces afterwards when he started talking to them in his normal British accent.
