Being Midwestern, I am used to the accent of (dating myself here) Walter Cronkite. But I've been following BBC shows long enough that I can watch Sherlock and Black Adder without a problem. And I noticed something first in 2004, when I started watching House MD.
Here's the Hugh Laurie I know:
By the way, that's Robbie Coltrain (Hagrid) and Rowan Atkinson (Mr. Bean/Johnny English) with him.
Here's Hugh Laurie as House:
Now, his American accent is perfect. No British inflections or British pronunciations (like issue, ISH-u vs. ISS-u).
CAVEAT: Do not get me wrong--I adore House MD and am excited to see Dr. Strange in November, and urge everyone to go watch these astounding actors!!
But the range of Laurie's voice in House is maybe three notes, as opposed to the full range in his native British accent. His House voice sounds very flat and limited to me. You can hear, as the seasons went on and he lived for a while in the US, the range increases. Listen. When he has a wider range of expression, you'll note his hair is grayer.
So here's Martin Freeman and Benedict Cumberbatch speaking their native tongue:
Have you heard Dr. Strange? While this movie will be AWESOME and I'll be buying a ticket and waiting in line, his accent reminds me strangely of Hugh Laurie's early House--the range isn't there. It's a tessitura of three notes.
But Martin Freeman--oh!! In Captain America: Civil War, he sounds like Martin Freeman, just with an American accent. He has the FULL range of his voice. I couldn't find a clip of Everett K. Ross, but here's another.
And just for fun, this one: