The ONLY acceptable accent should be the English accent, one whom anybody can understand.  I don't know the man's name but the newsreader for the BBC's Home Service was perfect where he spoke crisply and clearly: "This is the BBC Home Service, here is the news..."  I could listen to that man all day.  But you get some egocentric like Billy Connolly who gets all excited when telling his own jokes at eighteen to the dozen, by the time you've worked out what he's saying, he's five jokes on.  I couldn't listen to that man for five minutes - he'd need a subtitle/translation board.  

The Oxford accent - if it is indeed an accent, is easily understood by all, as is the Rhodesian accent.  Ian Smith could be understood without any problem.  Nobody had any problems understanding what our wonderful late Prime Minister Margaret Thatcher - G.R.H.S. was saying either.  There was a time not so many years back when entertainers would take elocution lessons to try to rid themselves of their north country accent.  Unfortunately things have taken a turn for the worse with the emphasis being on the north country dialect, the heavier the better.  

"Ooh, listen to me - I'm a Brummie, Glasweigen, Manchurian. Aberdonian etc."  

I'm glad to say I have no accent.