The number one perk of being a Brit in America is the accent. Unless you happen to live in New York or Los Angeles, hearing an English accent in the states can often be a good conversation starter and sometimes gives you better service (I think it’s because we say please and thank you more)
Sadly, however, when it comes to Americans trying to speak with an English accent, it’s often two types that causes a native Brit to groan. The worst is the default for most – the Cockney accent (think Dyk Van Dyk in Mary Poppins, this accent is about 95% of attempts) or an accent so upperclass it would make the Queen herself blush. But hey, it’s the thought that counts. My “Standard” American isn’t exactly of Hugh Laurie quality.
The following video is a good reminder of the huge amount of accents in the British isles and beyond (Ireland!) – although it does miss out at least two huge cities, Manchester and Birmingham, which have totally different sounds.