Do the people in England have something similar to our Nielsen Ratings? And what is their most watched show as of now?

Most-watched EPISODE(by total number of viewers) was The EastEnders (Den divorces Angie) with 30.15 million viewers on 25 December 1986.

Most-watched ONE-OFF EVENT(by total number of viewers)was the 1966 FIFA World Cup Final with 32.30 million viewers televised on 30 July 1966.

https://en.wikipedia.org/wiki/List_of_most-watched_television_episodes#United_Kingdom

24 million households have TVs, there are 56 million individual sets in British homes. The viewing figures are the result of painstaking research by the British Film Institute.

http://www.dailymail.co.uk/pages/live/articles/showbiz/showbiznews.html?in_article_id=346942&in_page_id=1773

BARB provides weekly audience figures for the UK.

www.barb.co.uk

Have a look at the website; it tells you all you need to know. And the most popular show NOW (and it has been for some time now) is the BBC1 soap opera EastEnders (though I prefer Coronation Street myself!)