Right, I've just been googling, and the Sutton 13 list (which was updated and expanded to take in 30 universities in 2011) wasn't a table of "universities noted for the quality of their education" either!
The Sutton Trust is a charity that aims to increase social mobility and increase access to education for under-privileged children.
The Sutton Trust initially picked a list of 13 UK universities which were identified as "research-led universities" and "those ranked the highest in an average of published university league tables", for the purposes of monitoring social mobility in 2000. These universities were in alphabetical order:[1]
^University of Birmingham, University of Bristol, University of Cambridge, Durham University, University of Edinburgh, Imperial College London, London School of Economics, University of Nottingham, University of Oxford, University of St Andrews, University College London, University of Warwick, University of York
In 2011, the Trust updated their methodology to take in the 30 "most highly selective" British universities, which were "also the 30 most selective according to the Times University Guide" for the purpose of illustrating the relative number of students from poor backgrounds enrolled here against the rest of the institutions. These are, in alphabetical order:[2]
Source: wikipedia