BBC News - The top 100 sites on the internet
news.bbc.co.uk
news.bbc.co.uk
I'm not sure which I trust more: the Nielson report, or Alexa. Unless Nielson actually installed tracking code on each of those websites or got traffic information from the respective companies, I don't see how they generated their rankings. The same goes for Alexa. I doubt that either ranking is particularly accurate.